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5c49b6a4 |
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08-Jan-2024 |
Lukas Bulwahn <lukas.bulwahn@gmail.com> |
vt: remove superfluous CONFIG_HW_CONSOLE The config HW_CONSOLE is always identical to the config VT and is not visible in the kernel's build menuconfig. So, CONFIG_HW_CONSOLE is redundant. Replace all references to CONFIG_HW_CONSOLE with CONFIG_VT and remove CONFIG_HW_CONSOLE. Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: https://lore.kernel.org/r/20240108134102.601-1-lukas.bulwahn@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
60234365 |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: fix up kernel-doc selection.c and vt.c still uses tabs in the kernel-doc. This misrenders the functions in the output -- sphinx misinterprets the description. So remove these tabs, incl. those around dashes. 'enum' keyword is needed before enum names. Fix that. Superfluous \n after the comments are also removed. They are not completely faulty, but this unifies all the kernel-doc in the files. Finally fix up the cross references. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-47-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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d1e22216 |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: document the rest of struct consw There are still members of struct consw which are not documented yet. Fix that up, so we can generate kernel-doc for that struct. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-46-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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b23bf1a4 |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: remove unused consw::con_flush_scrollback() consw::con_flush_scrollback() is unused since commit 973c096f6a85 (vgacon: remove software scrollback support). Drop it. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-45-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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f441aa3b |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: remove consw::con_getxy() After the previous patch, nobody sets that hook. So drop it completely. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-44-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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7cf01c92 |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: remove consw::con_screen_pos() After the previous patch, nobody sets that hook. So drop it completely. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-41-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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42822fab |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: change consw::con_set_origin() return type The return value of consw::con_set_origin() is only true/false, meaining if vc->vc_origin is set to vc->vc_screenbuf or not. So switch the type and returned values accordingly. And document the hook. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-39-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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4f596170 |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: make consw::con_font_default()'s name const It's a name after all and that is not supposed to be changed. So make it const to make this obvious. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-38-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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fd0f631f |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: make font of consw::con_font_set() const Provided the font parameter of consw::con_font_set() is not supposed to be changed, make it const. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-37-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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77e11093 |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: make types around consw::con_blank() bool Both the mode_switch parameter and the return value (a redraw needed) are true/false. So switch them to bool, so that users won't return -Eerrors or anything else. And document the hook. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-36-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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0a58d83d |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: use enum constants for VESA blanking modes Use the new enum for VESA constants. This improves type checking in consw::con_blank(). Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-35-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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ace4ebf9 |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: define a common enum for VESA blanking constants There are currently two places with VESA blanking constants definitions: fb.h and console.h. Extract/unify the two to a separate header (vesa.h). Given the fb's is in an uapi header, create the common header in uapi too. Note that instead of macros, an enum (vesa_blank_mode) is created. But the macros are kept too (they now expand to the enum constants), just in case someone in userspace performs some #ifdeffery. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: linux-kernel@vger.kernel.org Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: Thomas Zimmermann <tzimmermann@suse.de> Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-33-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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8d5cc8ee |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: make consw::con_switch() return a bool The non-zero (true) return value from consw::con_switch() means a redraw is needed. So make this return type a bool explicitly instead of int. The latter might imply that -Eerrors are expected. They are not. And document the hook. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-31-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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a292e3fc |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: remove CM_* constants There is no difference between CM_MOVE and CM_DRAW. Either of them enables the cursor. CM_ERASE then disables cursor. So get rid of all of them and use simple "bool enable". Note that this propagates down to the fbcon code. And document the hook. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-30-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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bfd7de49 |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: sanitize consw::con_putcs() parameters Similar to con_putc() in the previous patch: * make the pointer to charattr a pointer to u16, and * make x, y, and count unsigned as they are strictly non-negative. And again, document that hook. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-27-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
338c2810 |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: sanitize consw::con_putc() parameters Make parameters of consw::con_putc() saner: * x and y are unsigned now, as they cannot be negative, and * ca is made u16, as it is composed of two 8bit values (character and attribute). See the con_putcs() hook, u16/ushort is worked on there. And document the hook. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-26-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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559f01a0 |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: sanitize arguments of consw::con_clear() In consw::con_clear(): * Height is always 1, so drop it. * Offsets and width are always unsigned values, so re-type them as such. This needs a new __fbcon_clear() in the fbcon code to still handle height which might not be 1 when called internally. Note that tests for negative count/width are left in place -- they are taken care of in the next patches. And document the hook. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-22-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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dae3e6b6 |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: make init parameter of consw::con_init() a bool The 'init' parameter of consw::con_init() is true for the first call of the hook on a particular console. So make the parameter a bool. And document the hook. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Cc: linux-parisc@vger.kernel.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-21-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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7995c30d |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: make consw::con_debug_*() return void The return value of con_debug_enter() and con_debug_leave() is ignored on many fronts. So just don't propagate errors (the current implementations return 0 anyway) and make the return type a void. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-20-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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beccdcfa |
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21-Jan-2024 |
Jiri Slaby (SUSE) <jirislaby@kernel.org> |
tty: vt: pass vc_resize_user as a parameter It is pretty unfortunate to set vc_data::vc_resize_user in two callers of vc_do_resize(). vc_resize_user is immediately reset there (while remembering it). So instead of this back and forth, pass 'from_user' as a parameter. Notes on 'int user': * The name changes from 'user' to 'from_user' on some places to be consistent. * The type is bool now as 'int user' might evoke user's uid or whatever. Provided vc_resize() is called on many places and they need not to care about this parameter, its prototype is kept unchanged. Instead, it is now an inline calling a new __vc_resize() which implements the above. This patch makes the situation much more obvious. Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: linux-fbdev@vger.kernel.org Cc: dri-devel@lists.freedesktop.org Tested-by: Helge Deller <deller@gmx.de> # parisc STI console Link: https://lore.kernel.org/r/20240122110401.7289-8-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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1e3c8526 |
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12-Oct-2023 |
Tony Lindgren <tony@atomide.com> |
printk: Constify name for add_preferred_console() While adding a preferred console handling for serial_core for serial port hardware based device addressing, Jiri suggested we constify name for add_preferred_console(). The name gets copied anyways. This allows serial core to add a preferred console using serial drv->dev_name without copying it. Note that constifying options causes changes all over the place because of struct console for match(). Suggested-by: Jiri Slaby <jirislaby@kernel.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20231012064300.50221-2-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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545a4f89 |
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12-Oct-2023 |
Tony Lindgren <tony@atomide.com> |
printk: Check valid console index for preferred console Let's check for valid console index values for preferred console to avoid bogus console index numbers from kernel command line. Let's also return an error for negative index numbers for the preferred console. Unlike for device drivers, a negative index is not valid for the preferred console. Let's also constify idx while at it. Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20231012064300.50221-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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acfc7882 |
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09-Oct-2023 |
Arnd Bergmann <arnd@arndb.de> |
vgacon: remove screen_info dependency The vga console driver is fairly self-contained, and only used by architectures that explicitly initialize the screen_info settings. Chance every instance that picks the vga console by setting conswitchp to call a function instead, and pass a reference to the screen_info there. Reviewed-by: Javier Martinez Canillas <javierm@redhat.com> Acked-by: Khalid Azzi <khalid@gonehiking.org> Acked-by: Helge Deller <deller@gmx.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20231009211845.3136536-6-arnd@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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9757acd0 |
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16-Sep-2023 |
Thomas Gleixner <tglx@linutronix.de> |
printk: nbcon: Allow drivers to mark unsafe regions and check state For the write_atomic callback, the console driver may have unsafe regions that need to be appropriately marked. Provide functions that accept the nbcon_write_context struct to allow for the driver to enter and exit unsafe regions. Also provide a function for drivers to check if they are still the owner of the console. Co-developed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230916192007.608398-9-john.ogness@linutronix.de
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06653d57 |
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16-Sep-2023 |
Thomas Gleixner <tglx@linutronix.de> |
printk: nbcon: Add emit function and callback function for atomic printing Implement an emit function for nbcon consoles to output printk messages. It utilizes the lockless printk_get_next_message() and console_prepend_dropped() functions to retrieve/build the output message. The emit function includes the required safety points to check for handover/takeover and calls a new write_atomic callback of the console driver to output the message. It also includes proper handling for updating the nbcon console sequence number. A new nbcon_write_context struct is introduced. This is provided to the write_atomic callback and includes only the information necessary for performing atomic writes. Co-developed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230916192007.608398-8-john.ogness@linutronix.de
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ad56ebd1 |
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16-Sep-2023 |
Thomas Gleixner <tglx@linutronix.de> |
printk: nbcon: Add sequence handling Add an atomic_long_t field @nbcon_seq to the console struct to store the sequence number for nbcon consoles. For nbcon consoles this will be used instead of the non-atomic @seq field. The new field allows for safe atomic sequence number updates without requiring any locking. On 64bit systems the new field stores the full sequence number. On 32bit systems the new field stores the lower 32 bits of the sequence number, which are expanded to 64bit as needed by folding the values based on the sequence numbers available in the ringbuffer. For 32bit systems, having a 32bit representation in the console is sufficient. If a console ever gets more than 2^31 records behind the ringbuffer then this is the least of the problems. Co-developed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230916192007.608398-7-john.ogness@linutronix.de
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5634c90f |
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16-Sep-2023 |
Thomas Gleixner <tglx@linutronix.de> |
printk: nbcon: Add buffer management In case of hostile takeovers it must be ensured that the previous owner cannot scribble over the output buffer of the emergency/panic context. This is achieved by: - Adding a global output buffer instance for the panic context. This is the only situation where hostile takeovers can occur and there is always at most 1 panic context. - Allocating an output buffer per non-boot console upon console registration. This buffer is used by the console owner when not in panic context. (For boot consoles, the existing shared global legacy output buffer is used instead. Boot console printing will be synchronized with legacy console printing.) - Choosing the appropriate buffer is handled in the acquire/release functions. Co-developed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230916192007.608398-5-john.ogness@linutronix.de
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3a5bb251 |
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16-Sep-2023 |
Thomas Gleixner <tglx@linutronix.de> |
printk: nbcon: Add acquire/release logic Add per console acquire/release functionality. The state of the console is maintained in the "nbcon_state" atomic variable. The console is locked when: - The 'prio' field contains the priority of the context that owns the console. Only higher priority contexts are allowed to take over the lock. A value of 0 (NBCON_PRIO_NONE) means the console is not locked. - The 'cpu' field denotes on which CPU the console is locked. It is used to prevent busy waiting on the same CPU. Also it informs the lock owner that it has lost the lock in a more complex scenario when the lock was taken over by a higher priority context, released, and taken on another CPU with the same priority as the interrupted owner. The acquire mechanism uses a few more fields: - The 'req_prio' field is used by the handover approach to make the current owner aware that there is a context with a higher priority waiting for the friendly handover. - The 'unsafe' field allows to take over the console in a safe way in the middle of emitting a message. The field is set only when accessing some shared resources or when the console device is manipulated. It can be cleared, for example, after emitting one character when the console device is in a consistent state. - The 'unsafe_takeover' field is set when a hostile takeover took the console in an unsafe state. The console will stay in the unsafe state until re-initialized. The acquire mechanism uses three approaches: 1) Direct acquire when the console is not owned or is owned by a lower priority context and is in a safe state. 2) Friendly handover mechanism uses a request/grant handshake. It is used when the current owner has lower priority and the console is in an unsafe state. The requesting context: a) Sets its priority into the 'req_prio' field. b) Waits (with a timeout) for the owning context to unlock the console. c) Takes the lock and clears the 'req_prio' field. The owning context: a) Observes the 'req_prio' field set on exit from the unsafe console state. b) Gives up console ownership by clearing the 'prio' field. 3) Unsafe hostile takeover allows to take over the lock even when the console is an unsafe state. It is used only in panic() by the final attempt to flush consoles in a try and hope mode. Note that separate record buffers are used in panic(). As a result, the messages can be read and formatted without any risk even after using the hostile takeover in unsafe state. The release function simply clears the 'prio' field. All operations on @console::nbcon_state are atomic cmpxchg based to handle concurrency. The acquire/release functions implement only minimal policies: - Preference for higher priority contexts. - Protection of the panic CPU. All other policy decisions must be made at the call sites: - What is marked as an unsafe section. - Whether to spin-wait if there is already an owner and the console is in an unsafe state. - Whether to attempt an unsafe hostile takeover. The design allows to implement the well known: acquire() output_one_printk_record() release() The output of one printk record might be interrupted with a higher priority context. The new owner is supposed to reprint the entire interrupted record from scratch. Co-developed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230916192007.608398-3-john.ogness@linutronix.de
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6b93bb41 |
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16-Sep-2023 |
Thomas Gleixner <tglx@linutronix.de> |
printk: Add non-BKL (nbcon) console basic infrastructure The current console/printk subsystem is protected by a Big Kernel Lock, (aka console_lock) which has ill defined semantics and is more or less stateless. This puts severe limitations on the console subsystem and makes forced takeover and output in emergency and panic situations a fragile endeavour that is based on try and pray. The goal of non-BKL (nbcon) consoles is to break out of the console lock jail and to provide a new infrastructure that avoids the pitfalls and also allows console drivers to be gradually converted over. The proposed infrastructure aims for the following properties: - Per console locking instead of global locking - Per console state that allows to make informed decisions - Stateful handover and takeover As a first step, state is added to struct console. The per console state is an atomic_t using a 32bit bit field. Reserve state bits, which will be populated later in the series. Wire it up into the console register/unregister functionality. It was decided to use a bitfield because using a plain u32 with mask/shift operations resulted in uncomprehensible code. Co-developed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Thomas Gleixner (Intel) <tglx@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230916192007.608398-2-john.ogness@linutronix.de
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9e70a5e1 |
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17-Jul-2023 |
John Ogness <john.ogness@linutronix.de> |
printk: Add per-console suspended state Currently the global @console_suspended is used to determine if consoles are in a suspended state. Its primary purpose is to allow usage of the console_lock when suspended without causing console printing. It is synchronized by the console_lock. Rather than relying on the console_lock to determine suspended state, make it an official per-console state that is set within console->flags. This allows the state to be queried via SRCU. Remove @console_suspended. Console printing will still be avoided when suspended because console_is_usable() returns false when the new suspended flag is set for that console. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230717194607.145135-7-john.ogness@linutronix.de
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ffc1e089 |
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19-Jan-2023 |
Samuel Thibault <samuel.thibault@ens-lyon.org> |
VT: Add height parameter to con_font_get/set consw operations The current con_font_get/set API currently hardcodes a 32-pixel-tall limitation, which only dates from the old VGA hardware which could not handle taller fonts than that. This change just adds a vpitch parameter to release this constraint. Drivers which do not support vpitch != 32 can just return EINVAL when it is not 32, font loading tools will revert to trying 32 and succeed. This change makes the fbcon driver consider vpitch appropriately, thus making it able to load large fonts. Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Link: https://lore.kernel.org/r/20230119151934.932642243@ens-lyon.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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02b2396d |
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09-Jan-2023 |
Thomas Gleixner <tglx@linutronix.de> |
console: Document struct console Add kerneldoc comments to struct console. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230109100800.1085541-4-john.ogness@linutronix.de
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717a5651 |
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09-Jan-2023 |
Thomas Gleixner <tglx@linutronix.de> |
console: Use BIT() macros for @flags values Rather than manually calculating powers of 2, use the BIT() macros. Also take this opportunatity to cleanup and restructure the value comments into proper kerneldoc comments. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230109100800.1085541-3-john.ogness@linutronix.de
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6f883675 |
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16-Nov-2022 |
John Ogness <john.ogness@linutronix.de> |
printk, xen: fbfront: create/use safe function for forcing preferred With commit 9e124fe16ff2("xen: Enable console tty by default in domU if it's not a dummy") a hack was implemented to make sure that the tty console remains the console behind the /dev/console device. The main problem with the hack is that, after getting the console pointer to the tty console, it is assumed the pointer is still valid after releasing the console_sem. This assumption is incorrect and unsafe. Make the hack safe by introducing a new function console_force_preferred_locked() and perform the full operation under the console_list_lock. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-33-john.ogness@linutronix.de
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1fd4224a |
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16-Nov-2022 |
John Ogness <john.ogness@linutronix.de> |
console: introduce console_is_registered() Currently it is not possible for drivers to detect if they have already successfully registered their console. Several drivers have multiple paths that lead to console registration. To avoid attempting a 2nd registration (which leads to a WARN), drivers are implementing their own solution. Introduce console_is_registered() so drivers can easily identify if their console is currently registered. A _locked() variant is also provided if the caller is already holding the console_list_lock. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-22-john.ogness@linutronix.de
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100bdef2 |
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16-Nov-2022 |
John Ogness <john.ogness@linutronix.de> |
console: introduce wrappers to read/write console flags After switching to SRCU for console list iteration, some readers will begin readings console->flags as a data race. Locklessly reading console->flags provides a consistent value because there is at most one CPU modifying console->flags and that CPU is using only read-modify-write operations. Introduce a wrapper for SRCU iterators to read console flags. Introduce a matching wrapper to write to flags of registered consoles. Writing to flags of registered consoles is synchronized by the console_list_lock. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-13-john.ogness@linutronix.de
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4dc64682 |
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20-Nov-2022 |
John Ogness <john.ogness@linutronix.de> |
printk: introduce console_list_lock Currently there exist races in register_console(), where the types of registered consoles are checked (without holding the console_lock) and then after acquiring the console_lock, it is assumed that the list has not changed. Also, some code that performs console_unregister() make similar assumptions. It might be possible to fix these races using the console_lock. But it would require a complex analysis of all console drivers to make sure that the console_lock is not taken in match() and setup() callbacks. And we really prefer to split up and reduce the responsibilities of console_lock rather than expand its complexity. Therefore, introduce a new console_list_lock to provide full synchronization for any console list changes. In addition, also use console_list_lock for synchronization of console->flags updates. All flags are either static or modified only during the console registration. There are only two exceptions. The first exception is CON_ENABLED, which is also modified by console_start()/console_stop(). Therefore, these functions must also take the console_list_lock. The second exception is when the flags are modified by the console driver init code before the console is registered. These will be ignored because they are not visible to the rest of the system via the console_drivers list. Note that one of the various responsibilities of the console_lock is also intended to provide console list and console->flags synchronization. Later changes will update call sites relying on the console_lock for these purposes. Once all call sites have been updated, the console_lock will be relieved of synchronizing console_list and console->flags updates. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/87sficwokr.fsf@jogness.linutronix.de
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6c4afa79 |
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16-Nov-2022 |
John Ogness <john.ogness@linutronix.de> |
printk: Prepare for SRCU console list protection Provide an NMI-safe SRCU protected variant to walk the console list. Note that all console fields are now set before adding the console to the list to avoid the console becoming visible by SCRU readers before being fully initialized. This is a preparatory change for a new console infrastructure which operates independent of the console BKL. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Acked-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-4-john.ogness@linutronix.de
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d9a4af56 |
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16-Nov-2022 |
Thomas Gleixner <tglx@linutronix.de> |
printk: Convert console_drivers list to hlist Replace the open coded single linked list with a hlist so a conversion to SRCU protected list walks can reuse the existing primitives. Co-developed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-3-john.ogness@linutronix.de
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5831788a |
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23-Jun-2022 |
Petr Mladek <pmladek@suse.com> |
Revert "printk: add kthread console printers" This reverts commit 09c5ba0aa2fcfdadb17d045c3ee6f86d69270df7. This reverts commit b87f02307d3cfbda768520f0687c51ca77e14fc3. The testing of 5.19 release candidates revealed missing synchronization between early and regular console functionality. It would be possible to start the console kthreads later as a workaround. But it is clear that console lock serialized console drivers between each other. It opens a big area of possible problems that were not considered by people involved in the development and review. printk() is crucial for debugging kernel issues and console output is very important part of it. The number of consoles is huge and a proper review would take some time. As a result it need to be reverted for 5.19. Link: https://lore.kernel.org/r/YrBdjVwBOVgLfHyb@alley Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220623145157.21938-6-pmladek@suse.com
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2d9ef940 |
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23-Jun-2022 |
Petr Mladek <pmladek@suse.com> |
Revert "printk: extend console_lock for per-console locking" This reverts commit 8e274732115f63c1d09136284431b3555bd5cc56. The testing of 5.19 release candidates revealed missing synchronization between early and regular console functionality. It would be possible to start the console kthreads later as a workaround. But it is clear that console lock serialized console drivers between each other. It opens a big area of possible problems that were not considered by people involved in the development and review. printk() is crucial for debugging kernel issues and console output is very important part of it. The number of consoles is huge and a proper review would take some time. As a result it need to be reverted for 5.19. Link: https://lore.kernel.org/r/YrBdjVwBOVgLfHyb@alley Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220623145157.21938-5-pmladek@suse.com
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8e274732 |
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25-Apr-2022 |
John Ogness <john.ogness@linutronix.de> |
printk: extend console_lock for per-console locking Currently threaded console printers synchronize against each other using console_lock(). However, different console drivers are unrelated and do not require any synchronization between each other. Removing the synchronization between the threaded console printers will allow each console to print at its own speed. But the threaded consoles printers do still need to synchronize against console_lock() callers. Introduce a per-console mutex and a new console boolean field @blocked to provide this synchronization. console_lock() is modified so that it must acquire the mutex of each console in order to set the @blocked field. Console printing threads will acquire their mutex while printing a record. If @blocked was set, the thread will go back to sleep instead of printing. The reason for the @blocked boolean field is so that console_lock() callers do not need to acquire multiple console mutexes simultaneously, which would introduce unnecessary complexity due to nested mutex locking. Also, a new field was chosen instead of adding a new @flags value so that the blocked status could be checked without concern of reading inconsistent values due to @flags updates from other contexts. Threaded console printers also need to synchronize against console_trylock() callers. Since console_trylock() may be called from any context, the per-console mutex cannot be used for this synchronization. (mutex_trylock() cannot be called from atomic contexts.) Introduce a global atomic counter to identify if any threaded printers are active. The threaded printers will also check the atomic counter to identify if the console has been locked by another task via console_trylock(). Note that @console_sem is still used to provide synchronization between console_lock() and console_trylock() callers. A locking overview for console_lock(), console_trylock(), and the threaded printers is as follows (pseudo code): console_lock() { down(&console_sem); for_each_console(con) { mutex_lock(&con->lock); con->blocked = true; mutex_unlock(&con->lock); } /* console_lock acquired */ } console_trylock() { if (down_trylock(&console_sem) == 0) { if (atomic_cmpxchg(&console_kthreads_active, 0, -1) == 0) { /* console_lock acquired */ } } } threaded_printer() { mutex_lock(&con->lock); if (!con->blocked) { /* console_lock() callers blocked */ if (atomic_inc_unless_negative(&console_kthreads_active)) { /* console_trylock() callers blocked */ con->write(); atomic_dec(&console_lock_count); } } mutex_unlock(&con->lock); } The console owner and waiter logic now only applies between contexts that have taken the console_lock via console_trylock(). Threaded printers never take the console_lock, so they do not have a console_lock to handover. Tasks that have used console_lock() will block the threaded printers using a mutex and if the console_lock is handed over to an atomic context, it would be unable to unblock the threaded printers. However, the console_trylock() case is really the only scenario that is interesting for handovers anyway. @panic_console_dropped must change to atomic_t since it is no longer protected exclusively by the console_lock. Since threaded printers remain asleep if they see that the console is locked, they now must be explicitly woken in __console_unlock(). This means wake_up_klogd() calls following a console_unlock() are no longer necessary and are removed. Also note that threaded printers no longer need to check @console_suspended. The check for the @blocked field implicitly covers the suspended console case. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/878rrs6ft7.fsf@jogness.linutronix.de
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09c5ba0a |
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21-Apr-2022 |
John Ogness <john.ogness@linutronix.de> |
printk: add kthread console printers Create a kthread for each console to perform console printing. During normal operation (@system_state == SYSTEM_RUNNING), the kthread printers are responsible for all printing on their respective consoles. During non-normal operation, console printing is done as it has been: within the context of the printk caller or within irqwork triggered by the printk caller, referred to as direct printing. Since threaded console printers are responsible for all printing during normal operation, this also includes messages generated via deferred printk calls. If direct printing is in effect during a deferred printk call, the queued irqwork will perform the direct printing. To make it clear that this is the only time that the irqwork will perform direct printing, rename the flag PRINTK_PENDING_OUTPUT to PRINTK_PENDING_DIRECT_OUTPUT. Threaded console printers synchronize against each other and against console lockers by taking the console lock for each message that is printed. Note that the kthread printers do not care about direct printing. They will always try to print if new records are available. They can be blocked by direct printing, but will be woken again once direct printing is finished. Console unregistration is a bit tricky because the associated kthread printer cannot be stopped while the console lock is held. A policy is implemented that states: whichever task clears con->thread (under the console lock) is responsible for stopping the kthread. unregister_console() will clear con->thread while the console lock is held and then stop the kthread after releasing the console lock. For consoles that have implemented the exit() callback, the kthread is stopped before exit() is called. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-14-john.ogness@linutronix.de
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a699449b |
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21-Apr-2022 |
John Ogness <john.ogness@linutronix.de> |
printk: refactor and rework printing logic Refactor/rework printing logic in order to prepare for moving to threaded console printing. - Move @console_seq into struct console so that the current "position" of each console can be tracked individually. - Move @console_dropped into struct console so that the current drop count of each console can be tracked individually. - Modify printing logic so that each console independently loads, prepares, and prints its next record. - Remove exclusive_console logic. Since console positions are handled independently, replaying past records occurs naturally. - Update the comments explaining why preemption is disabled while printing from printk() context. With these changes, there is a change in behavior: the console replaying the log (formerly exclusive console) will no longer block other consoles. New messages appear on the other consoles while the newly added console is still replaying. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-10-john.ogness@linutronix.de
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6a2d2ddf |
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12-Nov-2021 |
Javier Martinez Canillas <javierm@redhat.com> |
drm: Move nomodeset kernel parameter to the DRM subsystem The "nomodeset" kernel cmdline parameter is handled by the vgacon driver but the exported vgacon_text_force() symbol is only used by DRM drivers. It makes much more sense for the parameter logic to be in the subsystem of the drivers that are making use of it. Let's move the vgacon_text_force() function and related logic to the DRM subsystem. While doing that, rename it to drm_firmware_drivers_only() and make it return true if "nomodeset" was used and false otherwise. This is a better description of the condition that the drivers are testing for. Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Javier Martinez Canillas <javierm@redhat.com> Acked-by: Thomas Zimmermann <tzimmermann@suse.de> Acked-by: Jani Nikula <jani.nikula@intel.com> Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://patchwork.freedesktop.org/patch/msgid/20211112133230.1595307-4-javierm@redhat.com
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027b5717 |
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02-Oct-2021 |
Pali Rohár <pali@kernel.org> |
serial: core: Fix initializing and restoring termios speed Since commit edc6afc54968 ("tty: switch to ktermios and new framework") termios speed is no longer stored only in c_cflag member but also in new additional c_ispeed and c_ospeed members. If BOTHER flag is set in c_cflag then termios speed is stored only in these new members. Therefore to correctly restore termios speed it is required to store also ispeed and ospeed members, not only cflag member. In case only cflag member with BOTHER flag is restored then functions tty_termios_baud_rate() and tty_termios_input_baud_rate() returns baudrate stored in c_ospeed / c_ispeed member, which is zero as it was not restored too. If reported baudrate is invalid (e.g. zero) then serial core functions report fallback baudrate value 9600. So it means that in this case original baudrate is lost and kernel changes it to value 9600. Simple reproducer of this issue is to boot kernel with following command line argument: "console=ttyXXX,86400" (where ttyXXX is the device name). For speed 86400 there is no Bnnn constant and therefore kernel has to represent this speed via BOTHER c_cflag. Which means that speed is stored only in c_ospeed and c_ispeed members, not in c_cflag anymore. If bootloader correctly configures serial device to speed 86400 then kernel prints boot log to early console at speed speed 86400 without any issue. But after kernel starts initializing real console device ttyXXX then speed is changed to fallback value 9600 because information about speed was lost. This patch fixes above issue by storing and restoring also ispeed and ospeed members, which are required for BOTHER flag. Fixes: edc6afc54968 ("[PATCH] tty: switch to ktermios and new framework") Cc: stable@vger.kernel.org Signed-off-by: Pali Rohár <pali@kernel.org> Link: https://lore.kernel.org/r/20211002130900.9518-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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a91bd622 |
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07-Jan-2021 |
Petr Mladek <pmladek@suse.com> |
Revert "init/console: Use ttynull as a fallback when there is no console" This reverts commit 757055ae8dedf5333af17b3b5b4b70ba9bc9da4e. The commit caused that ttynull was used as the default console on several systems[1][2][3]. As a result, the console was blank even when a better alternative existed. It happened when there was no console configured on the command line and ttynull_init() was the first initcall calling register_console(). Or it happened when /dev/ did not exist when console_on_rootfs() was called. It was not able to open /dev/console even though a console driver was registered. It tried to add ttynull console but it obviously did not help. But ttynull became the preferred console and was used by /dev/console when it was available later. The commit tried to fix a historical problem that have been there for ages. The primary motivation was the commit 3cffa06aeef7ece30f6 ("printk/console: Allow to disable console output by using console="" or console=null"). It provided a clean solution for a workaround that was widely used and worked only by chance. This revert causes that the console="" or console=null command line options will again work only by chance. These options will cause that a particular console will be preferred and the default (tty) ones will not get enabled. There will be no console registered at all. As a result there won't be stdin, stdout, and stderr for the init process. But it worked exactly this way even before. The proper solution has to fulfill many conditions: + Register ttynull only when explicitly required or as the ultimate fallback. + ttynull should get associated with /dev/console but it must not become preferred console when used as a fallback. Especially, it must still be possible to replace it by a better console later. Such a change requires clean up of the register_console() code. Otherwise, it would be even harder to follow. Especially, the use of has_preferred_console and CON_CONSDEV flag is tricky. The clean up is risky. The ordering of consoles is not well defined. And any changes tend to break existing user settings. Do the revert at the least risky solution for now. [1] https://lore.kernel.org/linux-kselftest/20201221144302.GR4077@smile.fi.intel.com/ [2] https://lore.kernel.org/lkml/d2a3b3c0-e548-7dd1-730f-59bc5c04e191@synopsys.com/ [3] https://patchwork.ozlabs.org/project/linux-um/patch/20210105120128.10854-1-thomas@m3y3r.de/ Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reported-by: Vineet Gupta <vgupta@synopsys.com> Reported-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Petr Mladek <pmladek@suse.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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757055ae |
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11-Nov-2020 |
Petr Mladek <pmladek@suse.com> |
init/console: Use ttynull as a fallback when there is no console stdin, stdout, and stderr standard I/O stream are created for the init process. They are not available when there is no console registered for /dev/console. It might lead to a crash when the init process tries to use them, see the commit 48021f98130880dd742 ("printk: handle blank console arguments passed in."). Normally, ttySX and ttyX consoles are used as a fallback when no consoles are defined via the command line, device tree, or SPCR. But there will be no console registered when an invalid console name is configured or when the configured consoles do not exist on the system. Users even try to avoid the console intentionally, for example, by using console="" or console=null. It is used on production systems where the serial port or terminal are not visible to users. Pushing messages to these consoles would just unnecessary slowdown the system. Make sure that stdin, stdout, stderr, and /dev/console are always available by a fallback to the existing ttynull driver. It has been implemented for exactly this purpose but it was used only when explicitly configured. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20201111135450.11214-2-pmladek@suse.com
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7a089ec7 |
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12-Nov-2020 |
Peilin Ye <yepeilin.cs@gmail.com> |
console: Delete unused con_font_copy() callback implementations Recently in commit 3c4e0dff2095 ("vt: Disable KD_FONT_OP_COPY") we disabled the KD_FONT_OP_COPY ioctl() option. Delete all the con_font_copy() callbacks, since we no longer use them. Mark KD_FONT_OP_COPY as "obsolete" in include/uapi/linux/kd.h, just like what we have done for PPPIOCDETACH in commit af8d3c7c001a ("ppp: remove the PPPIOCDETACH ioctl"). Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Link: https://patchwork.freedesktop.org/patch/msgid/c8d28007edf50de4387e1532eb3eb736db716f73.1605169912.git.yepeilin.cs@gmail.com
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d73568c4 |
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18-Aug-2020 |
Jiri Slaby <jirislaby@kernel.org> |
vt: make vc_data pointers const in selection.h There are many functions declared in selection.h which only read from struct vc_data passed as a parameter. Make all those uses const to hint the compiler a bit. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200818085706.12163-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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9a6f72d9 |
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15-Jun-2020 |
Jiri Slaby <jirislaby@kernel.org> |
vt: get rid of VT10.ID macros VT100ID is unused, but defined twice. Kill it. VT102ID is used only in respond_ID. Define there a variable with proper type and use that instead. Then drop both defines of VT102ID too. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200615074910.19267-9-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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77bc14f2 |
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15-Jun-2020 |
Jiri Slaby <jirislaby@kernel.org> |
vc: switch state to bool The code currently uses bitfields to store true-false values. Switch all of that to bools. Apart from the cleanup, it saves 20B of code as many shifts, ANDs, and ORs became simple movzb's. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200615074910.19267-3-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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b84ae3dc |
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15-Jun-2020 |
Jiri Slaby <jirislaby@kernel.org> |
vt: introduce enum vc_intensity for intensity Introduce names (en enum) for 0, 1, and 2 constants. We now have VCI_HALF_BRIGHT, VCI_NORMAL, and VCI_BOLD instead. Apart from the cleanup, 1) the enum allows for better type checking, and 2) this saves some code. No more fiddling with bits is needed in assembly now. (OTOH, the structure is larger.) Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20200615074910.19267-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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33225d7b |
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13-Feb-2020 |
Benjamin Herrenschmidt <benh@kernel.crashing.org> |
printk: Correctly set CON_CONSDEV even when preferred console was not registered CON_CONSDEV flag was historically used to put/keep the preferred console first in console_drivers list. Where the preferred console is the last on the command line. The ordering is important only when opening /dev/console: + tty_kopen() + tty_lookup_driver() + console_device() The flag was originally an implementation detail. But it was later made accessible from userspace via /proc/consoles. It was used, for example, by the tool "showconsole" to show the real tty accessible via /dev/console, see https://github.com/bitstreamout/showconsole Now, the current code sets CON_CONSDEV only for the preferred console or when a fallback console is added. The flag is not set when the preferred console is defined on the command line but it is not registered from some reasons. Simple solution is to set CON_CONSDEV flag for the first registered console. It will work most of the time because: + Most real consoles have console->device defined. + Boot consoles are removed in printk_late_init(). + unregister_console() moves CON_CONSDEV flag to the next console. Clean solution would require checking con->device when the preferred console is registered and in unregister_console(). Conclusion: Use the simple solution for now. It is better than the current state and good enough. The clean solution is not worth it. It would complicate the already complicated code without too much gain. Instead the code would deserve a complete rewrite. Link: https://lore.kernel.org/r/20200213095133.23176-4-pmladek@suse.com Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [pmladek@suse.com: Correct reasoning in the commit message, comment update.] Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
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ed31685c |
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03-Feb-2020 |
Andy Shevchenko <andriy.shevchenko@linux.intel.com> |
console: Introduce ->exit() callback Some consoles might require special operations on unregistering. For instance, serial console, when registered in the kernel, keeps power on for entire time, until it gets unregistered. Example of use: ->setup(console): pm_runtime_get(...); ->exit(console): pm_runtime_put(...); For such cases to have a balance we would provide ->exit() callback. Link: http://lkml.kernel.org/r/20200203133130.11591-7-andriy.shevchenko@linux.intel.com To: linux-kernel@vger.kernel.org To: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com>
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9167bd96 |
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15-Jan-2020 |
Arvind Sankar <nivedita@alum.mit.edu> |
sparc/console: kill off obsolete declarations commit 09d3f3f0e02c ("sparc: Kill PROM console driver.") missed removing the declarations of the deleted prom_con structure and prom_con_init function from console.h. Kill them off now. Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu> Signed-off-by: David S. Miller <davem@davemloft.net>
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de6da1e8 |
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17-May-2019 |
Feng Tang <feng.tang@intel.com> |
panic: add an option to replay all the printk message in buffer Currently on panic, kernel will lower the loglevel and print out pending printk msg only with console_flush_on_panic(). Add an option for users to configure the "panic_print" to replay all dmesg in buffer, some of which they may have never seen due to the loglevel setting, which will help panic debugging . [feng.tang@intel.com: keep the original console_flush_on_panic() inside panic()] Link: http://lkml.kernel.org/r/1556199137-14163-1-git-send-email-feng.tang@intel.com [feng.tang@intel.com: use logbuf lock to protect the console log index] Link: http://lkml.kernel.org/r/1556269868-22654-1-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1556095872-36838-1-git-send-email-feng.tang@intel.com Signed-off-by: Feng Tang <feng.tang@intel.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Aaro Koskinen <aaro.koskinen@nokia.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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56e6c104 |
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31-Jul-2018 |
Thomas Zimmermann <tzimmermann@suse.de> |
console: Replace #if 0 with atomic var 'ignore_console_lock_warning' The macro WARN_CONSOLE_UNLOCKED prints a warning when a thread enters the console's critical section without having acquired the console lock. The console lock can be ignored when debugging the console using printk, but this makes WARN_CONSOLE_UNLOCKED generate unnecessary warnings. The variable ignore_console_lock_warning temporarily disables WARN_CONSOLE_UNLOCKED. Developers interested in debugging the console's critical sections should increment it before entering the CS and decrement it after leaving the CS. Setting ignore_console_lock_warning is only for debugging. Regular operation should not manipulate it. Acknoledgements: This patch is based on an earlier version by Steven Rostedt. The use of atomic increment/decrement was suggested by Petr Mladek. Link: http://lkml.kernel.org/r/717e6337-e7a6-7a92-1c1b-8929a25696b5@suse.de Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Acked-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> [b.zolnierkie: use <linux/atomic.h>] Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
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83d83beb |
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28-Jun-2018 |
Hans de Goede <hdegoede@redhat.com> |
console/fbcon: Add support for deferred console takeover Currently fbcon claims fbdevs as soon as they are registered and takes over the console as soon as the first fbdev gets registered. This behavior is undesirable in cases where a smooth graphical bootup is desired, in such cases we typically want the contents of the framebuffer (typically a vendor logo) to stay in place as is. The current solution for this problem (on embedded systems) is to not enable fbcon. This commit adds a new FRAMEBUFFER_CONSOLE_DEFERRED_TAKEOVER config option, which when enabled defers fbcon taking over the console from the dummy console until the first text is displayed on the console. Together with the "quiet" kernel commandline option, this allows fbcon to still be used together with a smooth graphical bootup, having it take over the console as soon as e.g. an error message is logged. Note the choice to detect the first console output in the dummycon driver, rather then handling this entirely inside the fbcon code, was made after 2 failed attempts to handle this entirely inside the fbcon code. The fbcon code is woven quite tightly into the console code, making this to only feasible option. Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
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209f668c |
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26-Feb-2018 |
Kees Cook <keescook@chromium.org> |
console: Fill in struct consw argument names Reading the function declarations for the console callbacks lacks any hints as to what the arguments are. Instead of going and digging around in various implementations that may each only have a subset of the callbacks, name all the arguments in the declaration. This has no functional change. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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0c688614 |
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12-Apr-2017 |
Nicolas Pitre <nico@fluxnic.net> |
console: move console_init() out of tty_io.c All the console driver handling code lives in printk.c. Move console_init() there as well so console support can still be used when the TTY code is configured out. No logical changes from this patch. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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bcd375f7 |
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13-Jan-2017 |
Manuel Schölling <manuel.schoelling@gmx.de> |
console: Add callback to flush scrollback buffer to consw struct This new callback is in preparation for persistent scrollback buffer support for VGA consoles. With a single scrollback buffer for all consoles, we could flush the buffer just by invocating consw->con_switch(). But when each VGA console has its own scrollback buffer, we need a new callback to tell the video console driver which buffer to flush. Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de> Reviewed-by: Andrey Utkin <andrey_utkin@fastmail.com> Tested-by: Andrey Utkin <andrey_utkin@fastmail.com> Tested-by: Adam Borowski <kilobyte@angband.pl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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c6c7d83b |
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10-Nov-2016 |
Hans de Goede <hdegoede@redhat.com> |
Revert "console: don't prefer first registered if DT specifies stdout-path" This reverts commit 05fd007e4629 ("console: don't prefer first registered if DT specifies stdout-path"). The reverted commit changes existing behavior on which many ARM boards rely. Many ARM small-board-computers, like e.g. the Raspberry Pi have both a video output and a serial console. Depending on whether the user is using the device as a more regular computer; or as a headless device we need to have the console on either one or the other. Many users rely on the kernel behavior of the console being present on both outputs, before the reverted commit the console setup with no console= kernel arguments on an ARM board which sets stdout-path in dt would look like this: [root@localhost ~]# cat /proc/consoles ttyS0 -W- (EC p a) 4:64 tty0 -WU (E p ) 4:1 Where as after the reverted commit, it looks like this: [root@localhost ~]# cat /proc/consoles ttyS0 -W- (EC p a) 4:64 This commit reverts commit 05fd007e4629 ("console: don't prefer first registered if DT specifies stdout-path") restoring the original behavior. Fixes: 05fd007e4629 ("console: don't prefer first registered if DT specifies stdout-path") Link: http://lkml.kernel.org/r/20161104121135.4780-2-hdegoede@redhat.com Signed-off-by: Hans de Goede <hdegoede@redhat.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Thorsten Leemhuis <regressions@leemhuis.info> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tejun Heo <tj@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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d705ff38 |
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03-Oct-2016 |
Jiri Slaby <jirislaby@kernel.org> |
tty: vt, cleanup and document con_scroll Scrolling helpers scrup and scrdown both accept 'top' and 'bottom' as unsigned int. Number of lines 'nr' is accepted as int, but all callers pass down unsigned too. So change the type of 'nr' to unsigned too. Now, promote unsigned int from the helpers up to the con_scroll hook which actually accepted all those as signed int. Next, the 'dir' parameter can have only two values and we define constants for that: SM_UP and SM_DOWN. Switch them to enum and do proper type checking on 'dir' too. Finally, document the behaviour of the hook. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Thomas Winischhofer <thomas@winischhofer.net> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: <linux-fbdev@vger.kernel.org> Cc: <linux-usb@vger.kernel.org> Cc: <linux-parisc@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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05fd007e |
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07-Oct-2016 |
Paul Burton <paulburton@kernel.org> |
console: don't prefer first registered if DT specifies stdout-path If a device tree specifies a preferred device for kernel console output via the stdout-path or linux,stdout-path chosen node properties or the stdout alias then the kernel ought to honor it & output the kernel console to that device. As it stands, this isn't the case. Whilst we parse the stdout-path properties & set an of_stdout variable from of_alias_scan(), and use that from of_console_check() to determine whether to add a console device as a preferred console whilst registering it, we also prefer the first registered console if no other has been selected at the time of its registration. This means that if a console other than the one the device tree selects via stdout-path is registered first, we will switch to using it & when the stdout-path console is later registered the call to add_preferred_console() via of_console_check() is too late to do anything useful. In practice this seems to mean that we switch to the dummy console device fairly early & see no further console output: Console: colour dummy device 80x25 console [tty0] enabled bootconsole [ns16550a0] disabled Fix this by not automatically preferring the first registered console if one is specified by the device tree. This allows consoles to be registered but not enabled, and once the driver for the console selected by stdout-path calls of_console_check() the driver will be added to the list of preferred consoles before any other console has been enabled. When that console is then registered via register_console() it will be enabled as expected. Link: http://lkml.kernel.org/r/20160809151937.26118-1-paul.burton@imgtec.com Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Tejun Heo <tj@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Ivan Delalande <colona@arista.com> Cc: Thierry Reding <treding@nvidia.com> Cc: Borislav Petkov <bp@suse.de> Cc: Jan Kara <jack@suse.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Joe Perches <joe@perches.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Frank Rowand <frowand.list@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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52ad1f38 |
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23-Jun-2016 |
Jiri Slaby <jirislaby@kernel.org> |
tty: vt, remove consw->con_bmove It is never called since commit 81732c3b2fede (tty vt: Fix line garbage in virtual console on command line edition) in 3.7. So remove all the callbacks. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Thomas Winischhofer <thomas@winischhofer.net> Cc: linux-usb@vger.kernel.org Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: linux-parisc@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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709280da |
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23-Jun-2016 |
Jiri Slaby <jirislaby@kernel.org> |
tty: vt, consw->con_set_palette cleanup * allow NULL consw->con_set_palette (some consoles define an empty hook) * => remove empty hooks now * return value of consw->con_set_palette is never checked => make the function void * document consw->con_set_palette a bit Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Thomas Winischhofer <thomas@winischhofer.net> Cc: linux-usb@vger.kernel.org Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: linux-parisc@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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97293de9 |
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23-Jun-2016 |
Jiri Slaby <jirislaby@kernel.org> |
tty: vt, consw->con_scrolldelta cleanup * allow NULL consw->con_scrolldelta (some consoles define an empty hook) * => remove empty hooks now * return value of consw->con_scrolldelta is never checked => make the function void * document consw->con_scrolldelta a bit Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Thomas Winischhofer <thomas@winischhofer.net> Cc: linux-usb@vger.kernel.org Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com> Cc: Tomi Valkeinen <tomi.valkeinen@ti.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: linux-fbdev@vger.kernel.org Cc: linux-parisc@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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8ede5cce |
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31-Mar-2016 |
Jiri Slaby <jirislaby@kernel.org> |
tty: vt, make color_table const This means all ->con_set_palette have to have the second parameter const too now. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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44debe7a |
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30-Mar-2016 |
Daniel Vetter <daniel.vetter@ffwll.ch> |
vgacon: dummy implementation for vgacon_text_force This allows us to ditch a ton of ugly #ifdefs from a bunch of drm modeset drivers. v2: Make the dummy function actually return a sane value, spotted by Ville. v3: Because the patch is still in limbo there's no more drivers to convert, noticed by Emil. v4: Rebase once more, because hooray. I'll just go ahead an apply this one later on to drm-misc. Cc: Emil Velikov <emil.l.velikov@gmail.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com> Reviewed-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
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8d91f8b1 |
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15-Jan-2016 |
Tejun Heo <tj@kernel.org> |
printk: do cond_resched() between lines while outputting to consoles @console_may_schedule tracks whether console_sem was acquired through lock or trylock. If the former, we're inside a sleepable context and console_conditional_schedule() performs cond_resched(). This allows console drivers which use console_lock for synchronization to yield while performing time-consuming operations such as scrolling. However, the actual console outputting is performed while holding irq-safe logbuf_lock, so console_unlock() clears @console_may_schedule before starting outputting lines. Also, only a few drivers call console_conditional_schedule() to begin with. This means that when a lot of lines need to be output by console_unlock(), for example on a console registration, the task doing console_unlock() may not yield for a long time on a non-preemptible kernel. If this happens with a slow console devices, for example a serial console, the outputting task may occupy the cpu for a very long time. Long enough to trigger softlockup and/or RCU stall warnings, which in turn pile more messages, sometimes enough to trigger the next cycle of warnings incapacitating the system. Fix it by making console_unlock() insert cond_resched() between lines if @console_may_schedule. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Calvin Owens <calvinowens@fb.com> Acked-by: Jan Kara <jack@suse.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Kyle McMartin <kyle@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
6fe29354 |
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25-Jun-2015 |
Tejun Heo <tj@kernel.org> |
printk: implement support for extended console drivers printk log_buf keeps various metadata for each message including its sequence number and timestamp. The metadata is currently available only through /dev/kmsg and stripped out before passed onto console drivers. We want this metadata to be available to console drivers too so that console consumers can get full information including the metadata and dictionary, which among other things can be used to detect whether messages got lost in transit. This patch implements support for extended console drivers. Consoles can indicate that they want extended messages by setting the new CON_EXTENDED flag and they'll be fed messages formatted the same way as /dev/kmsg. "<level>,<sequnum>,<timestamp>,<contflag>;<message text>\n" If extended consoles exist, in-kernel fragment assembly is disabled. This ensures that all messages emitted to consoles have full metadata including sequence number. The contflag carries enough information to reassemble the fragments from the reader side trivially. Note that this only affects /dev/kmsg. Regular console and /proc/kmsg outputs are not affected by this change. * Extended message formatting for console drivers is enabled iff there are registered extended consoles. * Comment describing /dev/kmsg message format updated to add missing contflag field and help distinguishing variable from verbatim terms. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: David Miller <davem@davemloft.net> Cc: Kay Sievers <kay@vrfy.org> Reviewed-by: Petr Mladek <pmladek@suse.cz> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
c7cef0a8 |
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09-Mar-2015 |
Peter Hurley <peter@hurleysoftware.com> |
console: Add extensible console matching Add match() method to struct console which allows the console to perform console command line matching instead of (or in addition to) default console matching (ie., by fixed name and index). The match() method returns 0 to indicate a successful match; normal console matching occurs if no match() method is defined or the match() method returns non-zero. The match() method is expected to set the console index if required. Re-implement earlycon-to-console-handoff with direct matching of "console=uart|uart8250,..." to the 8250 ttyS console. Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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50539dd4 |
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08-May-2013 |
Wang YanQing <udknight@gmail.com> |
vt: delete unneeded function unregister_con_driver Now there is no place use unregister_con_driver, and we can achieve unregister_con_driver's function with unregister_con_driver easily, so just delete it to reduce code size and duplication. Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
dc964189 |
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08-May-2013 |
Wang YanQing <udknight@gmail.com> |
vt: delete unneeded functions register_con_driver|take_over_console Now there is no place use register_con_driver|take_over_console, and we can achieve their function with do_register_con_driver| do_take_over_console easily, so just delete them to reduce code duplication. Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
d0380e6c |
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29-Apr-2013 |
Thomas Gleixner <tglx@linutronix.de> |
early_printk: consolidate random copies of identical code The early console implementations are the same all over the place. Move the print function to kernel/printk and get rid of the copies. [akpm@linux-foundation.org: arch/mips/kernel/early_printk.c needs kernel.h for va_list] [paul.gortmaker@windriver.com: sh4: make the bios early console support depend on EARLY_PRINTK] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Mike Frysinger <vapier@gentoo.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Richard Weinberger <richard@nod.at> Reviewed-by: Ingo Molnar <mingo@kernel.org> Tested-by: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
e93a9a86 |
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24-Jan-2013 |
Takashi Iwai <tiwai@suse.de> |
fb: Yet another band-aid for fixing lockdep mess I've still got lockdep warnings even after Alan's patch, and it seems that yet more band aids are required to paper over similar paths for unbind_con_driver() and unregister_con_driver(). After this hack, lockdep warnings are finally gone. Signed-off-by: Takashi Iwai <tiwai@suse.de> Cc: Alan Cox <alan@linux.intel.com> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Jiri Kosina <jkosina@suse.cz> Cc: stable <stable@vger.kernel.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
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#
50e244cc |
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24-Jan-2013 |
Alan Cox <alan@linux.intel.com> |
fb: rework locking to fix lock ordering on takeover Adjust the console layer to allow a take over call where the caller already holds the locks. Make the fb layer lock in order. This is partly a band aid, the fb layer is terminally confused about the locking rules it uses for its notifiers it seems. [akpm@linux-foundation.org: remove stray non-ascii char, tidy comment] [akpm@linux-foundation.org: export do_take_over_console()] [airlied: cleanup another non-ascii char] Signed-off-by: Alan Cox <alan@linux.intel.com> Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Jiri Kosina <jkosina@suse.cz> Cc: stable <stable@vger.kernel.org> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dave Airlie <airlied@redhat.com>
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#
4f73bc4d |
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17-Jan-2013 |
Joe Millenbach <jmillenbach@gmail.com> |
tty: Added a CONFIG_TTY option to allow removal of TTY The option allows you to remove TTY and compile without errors. This saves space on systems that won't support TTY interfaces anyway. bloat-o-meter output is below. The bulk of this patch consists of Kconfig changes adding "depends on TTY" to various serial devices and similar drivers that require the TTY layer. Ideally, these dependencies would occur on a common intermediate symbol such as SERIO, but most drivers "select SERIO" rather than "depends on SERIO", and "select" does not respect dependencies. bloat-o-meter output comparing our previous minimal to new minimal by removing TTY. The list is filtered to not show removed entries with awk '$3 != "-"' as the list was very long. add/remove: 0/226 grow/shrink: 2/14 up/down: 6/-35356 (-35350) function old new delta chr_dev_init 166 170 +4 allow_signal 80 82 +2 static.__warned 143 142 -1 disallow_signal 63 62 -1 __set_special_pids 95 94 -1 unregister_console 126 121 -5 start_kernel 546 541 -5 register_console 593 588 -5 copy_from_user 45 40 -5 sys_setsid 128 120 -8 sys_vhangup 32 19 -13 do_exit 1543 1526 -17 bitmap_zero 60 40 -20 arch_local_irq_save 137 117 -20 release_task 674 652 -22 static.spin_unlock_irqrestore 308 260 -48 Signed-off-by: Joe Millenbach <jmillenbach@gmail.com> Reviewed-by: Jamey Sharp <jamey@minilop.net> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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f2f0945e |
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28-Sep-2012 |
Arnd Bergmann <arnd@arndb.de> |
tty/console: fix warnings in drivers/tty/serial/kgdboc.c The con_debug_leave/con_debug_enter functions are stubbed out by defining them to (0), which causes harmless build warnings. Using proper inline functions is the normal way to deal with this. Without this patch, building the ARM bcm2835_defconfig results in: drivers/tty/serial/kgdboc.c: In function 'kgdboc_pre_exp_handler': drivers/tty/serial/kgdboc.c:279:3: warning: statement with no effect [-Wunused-value] drivers/tty/serial/kgdboc.c: In function 'kgdboc_post_exp_handler': drivers/tty/serial/kgdboc.c:293:3: warning: statement with no effect [-Wunused-value] Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
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#
90ab5ee9 |
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12-Jan-2012 |
Rusty Russell <rusty@rustcorp.com.au> |
module_param: make bool parameters really bool (drivers & misc) module_param(bool) used to counter-intuitively take an int. In fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy trick. It's time to remove the int/unsigned int option. For this version it'll simply give a warning, but it'll break next kernel version. Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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ac751efa |
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25-Jan-2011 |
Torben Hohn <torbenh@gmx.de> |
console: rename acquire/release_console_sem() to console_lock/unlock() The -rt patches change the console_semaphore to console_mutex. As a result, a quite large chunk of the patches changes all acquire/release_console_sem() to acquire/release_console_mutex() This commit makes things use more neutral function names which dont make implications about the underlying lock. The only real change is the return value of console_trylock which is inverted from try_acquire_console_sem() This patch also paves the way to switching console_sem from a semaphore to a mutex. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: make console_trylock return 1 on success, per Geert] Signed-off-by: Torben Hohn <torbenh@gmx.de> Cc: Thomas Gleixner <tglx@tglx.de> Cc: Greg KH <gregkh@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
fbc92a34 |
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01-Dec-2010 |
Kay Sievers <kay.sievers@vrfy.org> |
tty: add 'active' sysfs attribute to tty0 and console device tty: add 'active' sysfs attribute to tty0 and console device Userspace can query the actual virtual console, and the configured console devices behind /dev/tt0 and /dev/console. The last entry in the list of devices is the active device, analog to the console= kernel command line option. The attribute supports poll(), which is raised when the virtual console is changed or /dev/console is reconfigured. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> index 0000000..b138b66
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a75d946f |
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04-Nov-2010 |
Jiri Slaby <jirislaby@kernel.org> |
console: move for_each_console to linux/console.h Move it out of printk.c so that we can use it all over the code. There are some potential users which will be converted to that macro in next patches. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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#
9261ec1a |
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06-Aug-2010 |
Jason Wessel <jason.wessel@windriver.com> |
console: Fix compilation regression A regression of building without CONFIG_HW_CONSOLE was introduced with commit b45cfba4e9005d64d419718e7ff7f7cab44c1994 (vt,console,kdb: implement atomic console enter/leave functions). ERROR: "con_debug_enter" [drivers/serial/kgdboc.ko] undefined! ERROR: "vc_cons" [drivers/serial/kgdboc.ko] undefined! ERROR: "fg_console" [drivers/serial/kgdboc.ko] undefined! ERROR: "con_debug_leave" [drivers/serial/kgdboc.ko] undefined! When there is no HW console the con_debug_enter and con_debug_leave functions should have no code. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> CC: Jesse Barnes <jbarnes@virtuousgeek.org> Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
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#
b45cfba4 |
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05-Aug-2010 |
Jesse Barnes <jbarnes@virtuousgeek.org> |
vt,console,kdb: implement atomic console enter/leave functions These functions allow the kernel debugger to save and restore the state of the system console. Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> CC: David Airlie <airlied@linux.ie> CC: Andrew Morton <akpm@linux-foundation.org>
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4995f8ef |
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09-Mar-2009 |
Kay Sievers <kay.sievers@vrfy.org> |
vcs: hook sysfs devices into object lifetime instead of "binding" During bootup performance tracing I noticed many occurrences of vca* device creation and removal, leading to the usual userspace uevent processing, which are, in this case, rather pointless. A simple test showing the kernel timing (not including all the work userspace has to do), gives us these numbers: $ time for i in `seq 1000`; do echo a > /dev/tty2; done real 0m1.142s user 0m0.015s sys 0m0.540s If we move the hook for the vcs* driver core devices from the tty "binding" to the vc allocation/deallocation, which is what the vcs* devices represent, we get the following numbers: $ time for i in `seq 1000`; do echo a > /dev/tty2; done real 0m0.152s user 0m0.030s sys 0m0.072s Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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f453ba04 |
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07-Nov-2008 |
Dave Airlie <airlied@redhat.com> |
DRM: add mode setting support Add mode setting support to the DRM layer. This is a fairly big chunk of work that allows DRM drivers to provide full output control and configuration capabilities to userspace. It was motivated by several factors: - the fb layer's APIs aren't suited for anything but simple configurations - coordination between the fb layer, DRM layer, and various userspace drivers is poor to non-existent (radeonfb excepted) - user level mode setting drivers makes displaying panic & oops messages more difficult - suspend/resume of graphics state is possible in many more configurations with kernel level support This commit just adds the core DRM part of the mode setting APIs. Driver specific commits using these new structure and APIs will follow. Co-authors: Jesse Barnes <jbarnes@virtuousgeek.org>, Jakob Bornecrantz <jakob@tungstengraphics.com> Contributors: Alan Hourihane <alanh@tungstengraphics.com>, Maarten Maathuis <madman2003@gmail.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: Dave Airlie <airlied@redhat.com>
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#
9e124fe1 |
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26-May-2008 |
Markus Armbruster <armbru@redhat.com> |
xen: Enable console tty by default in domU if it's not a dummy Without console= arguments on the kernel command line, the first console to register becomes enabled and the preferred console (the one behind /dev/console). This is normally tty (assuming CONFIG_VT_CONSOLE is enabled, which it commonly is). This is okay as long tty is a useful console. But unless we have the PV framebuffer, and it is enabled for this domain, tty0 in domU is merely a dummy. In that case, we want the preferred console to be the Xen console hvc0, and we want it without having to fiddle with the kernel command line. Commit b8c2d3dfbc117dff26058fbac316b8acfc2cb5f7 did that for us. Since we now have the PV framebuffer, we want to enable and prefer tty again, but only when PVFB is enabled. But even then we still want to enable the Xen console as well. Problem: when tty registers, we can't yet know whether the PVFB is enabled. By the time we can know (xenstore is up), the console setup game is over. Solution: enable console tty by default, but keep hvc as the preferred console. Change the preferred console to tty when PVFB probes successfully, unless we've been given console kernel parameters. Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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f7511d5f |
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30-Apr-2008 |
Samuel Thibault <samuel.thibault@ens-lyon.org> |
Basic braille screen reader support This adds a minimalistic braille screen reader support. This is meant to be used by blind people e.g. on boot failures or when / cannot be mounted etc and thus the userland screen readers can not work. [akpm@linux-foundation.org: fix exports] Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Cc: Jiri Kosina <jikos@jikos.cz> Cc: Dmitry Torokhov <dtor@mail.ru> Acked-by: Alan Cox <alan@redhat.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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8f4ce8c3 |
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18-Oct-2007 |
Andres Salomon <dilinger@debian.org> |
serial: turn serial console suspend a boot rather than compile time option Currently, there's a CONFIG_DISABLE_CONSOLE_SUSPEND that allows one to stop the serial console from being suspended when the rest of the machine goes to sleep. This is incredibly useful for debugging power management-related things; however, having it as a compile-time option has proved to be incredibly inconvenient for us (OLPC). There are plenty of times that we want serial console to not suspend, but for the most part we'd like serial console to be suspended. This drops CONFIG_DISABLE_CONSOLE_SUSPEND, and replaces it with a kernel boot parameter (no_console_suspend). By default, the serial console will be suspended along with the rest of the system; by passing 'no_console_suspend' to the kernel during boot, serial console will remain alive during suspend. For now, this is pretty serial console specific; further fixes could be applied to make this work for things like netconsole. Signed-off-by: Andres Salomon <dilinger@debian.org> Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Nigel Cunningham <nigel@suspend2.net> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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e400b6ec |
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16-Oct-2007 |
Antonino A. Daplas <adaplas@gmail.com> |
vt/vgacon: Check if screen resize request comes from userspace Various console drivers are able to resize the screen via the con_resize() hook. This hook is also visible in userspace via the TIOCWINSZ, VT_RESIZE and VT_RESIZEX ioctl's. One particular utility, SVGATextMode, expects that con_resize() of the VGA console will always return success even if the resulting screen is not compatible with the hardware. However, this particular behavior of the VGA console, as reported in Kernel Bugzilla Bug 7513, can cause undefined behavior if the user starts with a console size larger than 80x25. To work around this problem, add an extra parameter to con_resize(). This parameter is ignored by drivers except for vgacon. If this parameter is non-zero, then the resize request came from a VT_RESIZE or VT_RESIZEX ioctl and vgacon will always return success. If this parameter is zero, vgacon will return -EINVAL if the requested size is not compatible with the hardware. The latter is the more correct behavior. With this change, SVGATextMode should still work correctly while in-kernel and stty resize calls can expect correct behavior from vgacon. Signed-off-by: Antonino Daplas <adaplas@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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0a3021f4 |
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16-Jul-2007 |
Robert P. J. Day <rpjday@mindspring.com> |
Remove unnecessary includes of spinlock.h under include/linux Remove the obviously unnecessary includes of <linux/spinlock.h> under the include/linux/ directory, and fix the couple errors that are introduced as a result of that. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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18a8bd94 |
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16-Jul-2007 |
Yinghai Lu <Yinghai.Lu@Sun.COM> |
serial: convert early_uart to earlycon for 8250 Beacuse SERIAL_PORT_DFNS is removed from include/asm-i386/serial.h and include/asm-x86_64/serial.h. the serial8250_ports need to be probed late in serial initializing stage. the console_init=>serial8250_console_init=> register_console=>serial8250_console_setup will return -ENDEV, and console ttyS0 can not be enabled at that time. need to wait till uart_add_one_port in drivers/serial/serial_core.c to call register_console to get console ttyS0. that is too late. Make early_uart to use early_param, so uart console can be used earlier. Make it to be bootconsole with CON_BOOT flag, so can use console handover feature. and it will switch to corresponding normal serial console automatically. new command line will be: console=uart8250,io,0x3f8,9600n8 console=uart8250,mmio,0xff5e0000,115200n8 or earlycon=uart8250,io,0x3f8,9600n8 earlycon=uart8250,mmio,0xff5e0000,115200n8 it will print in very early stage: Early serial console at I/O port 0x3f8 (options '9600n8') console [uart0] enabled later for console it will print: console handover: boot [uart0] -> real [ttyS0] Signed-off-by: <yinghai.lu@sun.com> Cc: Andi Kleen <ak@suse.de> Cc: Bjorn Helgaas <bjorn.helgaas@hp.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Gerd Hoffmann <kraxel@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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fa6ce9ab |
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08-May-2007 |
Jan Engelhardt <jengelh@linux01.gwdg.de> |
vt: add color support to the "underline" and "italic" attributes Add color support to the "underline" and "italic" attributes as in OpenBSD/NetBSD-style (vt220) and xterm. Signed-off-by: Jan Engelhardt <jengelh@gmx.de> Acked-by: "Antonino A. Daplas" <adaplas@pol.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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6ae9200f |
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08-May-2007 |
Andrew Morton <akpm@linux-foundation.org> |
enlarge console.name console.name[] is eight chars, but so is "earlyvga". So when we try to print console->name when using earlyvga it runs off the end of the string. Make it bigger. Diagnosed-by: Gerd Hoffmann <kraxel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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1b135431 |
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10-Feb-2007 |
Adrian Bunk <bunk@stusta.de> |
[PATCH] drivers/char/vc_screen.c: proper prototypes Add proper prototypes for two functions in drivers/char/vc_screen.c Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
3cb340ec |
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03-Oct-2006 |
Adrian Bunk <bunk@stusta.de> |
[PATCH] vt: proper prototypes for some console functions This patch adds proper prototypes to header files for three console init functions used on drivers/char/vt.c Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Antonino Daplas <adaplas@pol.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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c8eb8b40 |
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26-Sep-2006 |
Rafael J. Wysocki <rjw@rjwysocki.net> |
[PATCH] PM: make it possible to disable console suspending Change suspend_console() so that it waits for all consoles to flush the remaining messages and make it possible to switch the console suspending off with the help of a Kconfig option. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Stefan Seyfried <seife@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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3e795de7 |
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26-Jun-2006 |
Antonino A. Daplas <adaplas@gmail.com> |
[PATCH] VT binding: Add binding/unbinding support for the VT console The framebuffer console is now able to dynamically bind and unbind from the VT console layer. Due to the way the VT console layer works, the drivers themselves decide when to bind or unbind. However, it was decided that binding must be controlled, not by the drivers themselves, but by the VT console layer. With this, dynamic binding is possible for all VT console drivers, not just fbcon. Thus, the VT console layer will impose the following to all VT console drivers: - all registered VT console drivers will be entered in a private list - drivers can register themselves to the VT console layer, but they cannot decide when to bind or unbind. (Exception: To maintain backwards compatibility, take_over_console() will automatically bind the driver after registration.) - drivers can remove themselves from the list by unregistering from the VT console layer. A prerequisite for unregistration is that the driver must not be bound. The following functions are new in the vt.c: register_con_driver() - public function, this function adds the VT console driver to an internal list maintained by the VT console bind_con_driver() - private function, it binds the driver to the console take_over_console() is changed to call register_con_driver() followed by a bind_con_driver(). This is the only time drivers can decide when to bind to the VT layer. This is to maintain backwards compatibility. unbind_con_driver() - private function, it unbinds the driver from its console. The vacated consoles will be taken over by the default boot console driver. unregister_con_driver() - public function, removes the driver from the internal list maintained by the VT console. It will only succeed if the driver is currently unbound. con_is_bound() checks if the driver is currently bound or not give_up_console() is just a wrapper to unregister_con_driver(). There are also 3 additional functions meant to be called only by the tty layer for sysfs control: vt_bind() - calls bind_con_driver() vt_unbind() - calls unbind_con_driver() vt_show_drivers() - shows the list of registered drivers Most VT console drivers will continue to work as is, but might have problems when unbinding or binding which should be fixable with minimal changes. Signed-off-by: Antonino Daplas <adaplas@pol.net> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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76a8ad29 |
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25-Jun-2006 |
Michael Ellerman <michael@ellerman.id.au> |
[PATCH] Make printk work for really early debugging Currently printk is no use for early debugging because it refuses to actually print anything to the console unless cpu_online(smp_processor_id()) is true. The stated explanation is that console drivers may require per-cpu resources, or otherwise barf, because the system is not yet setup correctly. Fair enough. However some console drivers might be quite happy running early during boot, in fact we have one, and so it'd be nice if printk understood that. So I added a flag (which I would have called CON_BOOT, but that's taken) called CON_ANYTIME, which indicates that a console is happy to be called anytime, even if the cpu is not yet online. Tested on a Power 5 machine, with both a CON_ANYTIME driver and a bogus console driver that BUG()s if called while offline. No problems AFAICT. Built for i386 UP & SMP. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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557240b4 |
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19-Jun-2006 |
Linus Torvalds <torvalds@g5.osdl.org> |
Add support for suspending and resuming the whole console subsystem Trying to suspend/resume with console messages flying all around is doomed to failure, when the devices that the messages are trying to go to are being shut down. Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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1da177e4 |
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16-Apr-2005 |
Linus Torvalds <torvalds@ppc970.osdl.org> |
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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