ACPI: video: Handle fetching EDID that is longer than 256 bytes

The ACPI specification allows for an EDID to be up to 512 bytes but
the _DDC EDID fetching code will only try up to 256 bytes.

Modify the code to instead start at 512 bytes and work it's way
down instead.

As _DDC is now called up to 4 times on a machine debugging messages
are noisier than necessary. Decrease from info to debug.

Link: https://uefi.org/htmlspecs/ACPI_Spec_6_4_html/Apx_B_Video_Extensions/output-device-specific-methods.html#ddc-return-the-edid-for-this-device
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
[ rjw: Type mismatch fix, minor whitespace adjustment ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Add quirk for the Colorful X15 AT 23 Laptop

The Colorful X15 AT 23 ACPI video-bus device report spurious
ACPI_VIDEO_NOTIFY_CYCLE events resulting in spurious KEY_SWITCHVIDEOMODE
events being reported to userspace (and causing trouble there) when
an external screen plugged in.

Add a quirk setting the report_key_events mask to
REPORT_BRIGHTNESS_KEY_EVENTS so that the ACPI_VIDEO_NOTIFY_CYCLE
events will be ignored, while still reporting brightness up/down
hotkey-presses to userspace normally.

Signed-off-by: Yuluo Qiu <qyl27@outlook.com>
Co-developed-by: Celeste Liu <CoelacanthusHex@gmail.com>
Signed-off-by: Celeste Liu <CoelacanthusHex@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: check for error while searching for backlight device parent

If acpi_get_parent() called in acpi_video_dev_register_backlight()
fails, for example, because acpi_ut_acquire_mutex() fails inside
acpi_get_parent), this can lead to incorrect (uninitialized)
acpi_parent handle being passed to acpi_get_pci_dev() for detecting
the parent pci device.

Check acpi_get_parent() result and set parent device only in case of success.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 9661e92c10a9 ("acpi: tie ACPI backlight devices to PCI devices if possible")
Signed-off-by: Nikita Kiryushin <kiryushin@ancud.ru>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Drop should_check_lcd_flag()

Since commit 3dbc80a3e4c5 ("ACPI: video: Make backlight class device
registration a separate step (v2)") acpi_video# backlights are no longer
automatically registered. Instead they now only get registered when
the GPU/KMS driver calls acpi_video_register_backlight() which it only
does when it has detected an internal LCD panel.

This fixes the issue of sometimes a non-working acpi_video# backlight
showing up on Desktops / HDMI-sticks without an internal LCD display
in a more complete and robust manner then the LCD flag check which
gets enabled by the should_check_lcd_flag() helper does.

Therefor the should_check_lcd_flag() helper is no longer necessary.

The lcd_only flag itself is still necessary to only register
a single backlight device (for the right output) on the ESPRIMO Mobile
M9410 which has 2 ACPI video connector nodes with a _BCM control method,
which is the issue for which the flag was originally introduced in
commit e50b9be14ab0 ("ACPI / video: only register backlight for LCD
device").

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Use acpi_video_device for cooling-dev driver data

The acpi_video code was storing the acpi_video_device as driver_data
in the acpi_device children of the acpi_video_bus acpi_device.

But the acpi_video driver only binds to the bus acpi_device.
It uses, but does not bind to, the children. Since it is not
the driver it should not be using the driver_data of the children's
acpi_device-s.

Since commit 0d16710146a1 ("ACPI: bus: Set driver_data to NULL every
time .add() fails") the childen's driver_data ends up getting set
to NULL after a driver fails to bind to the children leading to a NULL
pointer deref in video_get_max_state when registering the cooling-dev:

[ 3.148958] BUG: kernel NULL pointer dereference, address: 0000000000000090
<snip>
[ 3.149015] Hardware name: Sony Corporation VPCSB2X9R/VAIO, BIOS R2087H4 06/15/2012
[ 3.149021] RIP: 0010:video_get_max_state+0x17/0x30 [video]
<snip>
[ 3.149105] Call Trace:
[ 3.149110] <TASK>
[ 3.149114] ? __die+0x23/0x70
[ 3.149126] ? page_fault_oops+0x171/0x4e0
[ 3.149137] ? exc_page_fault+0x7f/0x180
[ 3.149147] ? asm_exc_page_fault+0x26/0x30
[ 3.149158] ? video_get_max_state+0x17/0x30 [video 9b6f3f0d19d7b4a0e2df17a2d8b43bc19c2ed71f]
[ 3.149176] ? __pfx_video_get_max_state+0x10/0x10 [video 9b6f3f0d19d7b4a0e2df17a2d8b43bc19c2ed71f]
[ 3.149192] __thermal_cooling_device_register.part.0+0xf2/0x2f0
[ 3.149205] acpi_video_bus_register_backlight.part.0.isra.0+0x414/0x570 [video 9b6f3f0d19d7b4a0e2df17a2d8b43bc19c2ed71f]
[ 3.149227] acpi_video_register_backlight+0x57/0x80 [video 9b6f3f0d19d7b4a0e2df17a2d8b43bc19c2ed71f]
[ 3.149245] intel_acpi_video_register+0x68/0x90 [i915 1f3a758130b32ef13d301d4f8f78c7d766d57f2a]
[ 3.149669] intel_display_driver_register+0x28/0x50 [i915 1f3a758130b32ef13d301d4f8f78c7d766d57f2a]
[ 3.150064] i915_driver_probe+0x790/0xb90 [i915 1f3a758130b32ef13d301d4f8f78c7d766d57f2a]
[ 3.150402] local_pci_probe+0x45/0xa0
[ 3.150412] pci_device_probe+0xc1/0x260
<snip>

Fix this by directly using the acpi_video_device as devdata for
the cooling-device, which avoids the need to set driver-data on
the children at all.

Fixes: 0d16710146a1 ("ACPI: bus: Set driver_data to NULL every time .add() fails")
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/9718
Cc: 6.6+ <stable@vger.kernel.org> # 6.6+
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Use acpi_device_fix_up_power_children()

Commit 89c290ea7589 ("ACPI: video: Put ACPI video and its child devices
into D0 on boot") introduced calling acpi_device_fix_up_power_extended()
on the video card for which the ACPI video bus is the companion device.

This unnecessarily touches the power-state of the GPU itself, while
the issue it tries to address only requires calling _PS0 on the child
devices.

Touching the power-state of the GPU itself is causing suspend / resume
issues on e.g. a Lenovo ThinkPad W530.

Instead use acpi_device_fix_up_power_children(), which only touches
the child devices, to fix this.

Fixes: 89c290ea7589 ("ACPI: video: Put ACPI video and its child devices into D0 on boot")
Reported-by: Owen T. Heisler <writer@owenh.net>
Closes: https://lore.kernel.org/regressions/9f36fb06-64c4-4264-aaeb-4e1289e764c4@owenh.net/
Closes: https://gitlab.freedesktop.org/drm/nouveau/-/issues/273
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218124
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Owen T. Heisler <writer@owenh.net>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Cc: 6.6+ <stable@vger.kernel.org> # 6.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: bus: Add context argument to acpi_dev_install_notify_handler()

Add void *context arrgument to the list of arguments of
acpi_dev_install_notify_handler() and modify it to pass that argument
as context to acpi_install_notify_handler() instead of its first
argument which is problematic in general (for example, if platform
drivers used it, they would rather get struct platform_device pointers
or pointers to their private data from the context arguments of their
notify handlers).

Make all of the current callers of acpi_dev_install_notify_handler()
take this change into account so as to avoid altering the general
functionality.

Co-developed-by: Michal Wilczynski <michal.wilczynski@intel.com>
Signed-off-by: Michal Wilczynski <michal.wilczynski@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Fix NULL pointer dereference in acpi_video_bus_add()

acpi_video_bus_add_notify_handler() could free video->input and
set it to NULL on failure, but this failure would be missed in its
caller acpi_video_bus_add(). As a result, when an error happens in
acpi_dev_install_notify_handler(), acpi_video_bus_add() would call
acpi_video_bus_remove_notify_handler(), where a potential NULL pointer
video->input is dereferenced in input_unregister_device().

Fix this by adding a return value check and adjusting the following
error handling code.

Fixes: 6f7016819766 ("ACPI: video: Install Notify() handler directly")
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Put ACPI video and its child devices into D0 on boot

Screen brightness can only be changed once on HP ZBook Fury 16 G10.

The vendor reports that the issue is related to the fact that Linux doesn't
invoke _PS0 at boot for all ACPI devices, as expected by the platform firmware:

Scope (\_SB.PC00.GFX0)
{
Scope (DD1F)
{
Method (_PS0, 0, Serialized) // _PS0: Power State 0
{
If (CondRefOf (\_SB.PC00.LPCB.EC0.SSBC))
{
\_SB.PC00.LPCB.EC0.SSBC ()
}
}
...
}
...
}

The \_SB.PC00.GFX0.DD1F is the panel device, and its _PS0 needs to be
executed at the initialization time to make the brightness control work
properly.

_PS0 is not evaluated for this device, because _PSC is missing,
which violates the ACPI specification (ACPI 6.5, section 7.3.6).

Commit b3785492268f ("ACPI / PM: Do not power manage devices in unknown
initial states") tried to work around missing _PSC on platforms with
defective firmware, but got reverted due to a regression.

So the safest approach is to use acpi_device_fix_up_power_extended() to
put ACPI video and its child devices to D0 to address the issue at hand.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217683
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Install Notify() handler directly

Modify the ACPI video driver to install its own Notify() handler directly
instead of providing an ACPI driver .notify() callback.

This will allow the ACPI driver .notify() callback to be eliminated and
it will allow the ideo driver to be switched over to a platform one in
the future.

Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Michal Wilczynski <michal.wilczynski@intel.com>
[ rjw: Subject and changelog edits, whitespace adjustments ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Remove register_backlight_delay module option and code

Since commit 5aa9d943e9b6 ("ACPI: video: Don't enable fallback path for
creating ACPI backlight by default"), the delayed registering of
acpi_video# backlight devices has been disabled by default.

The few bugreports where this option was used as a workaround were all
cases where the GPU driver did not call acpi_video_register_backlight()
and the workaround was to pass video.register_backlight_delay=1.

With the recent "ACPI: video: Make acpi_backlight=video work independent
from GPU driver" changes acpi_backlight=video can be used to achieve
the same result. So there is no need for the register_backlight_delay
option + code anymore.

Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Make acpi_backlight=video work independent from GPU driver

Commit 3dbc80a3e4c5 ("ACPI: video: Make backlight class device
registration a separate step (v2)") combined with
commit 5aa9d943e9b6 ("ACPI: video: Don't enable fallback path for
creating ACPI backlight by default")

Means that the video.ko code now fully depends on the GPU driver calling
acpi_video_register_backlight() for the acpi_video# backlight class
devices to get registered.

This means that if the GPU driver does not do this, acpi_backlight=video
on the cmdline, or DMI quirks for selecting acpi_video# will not work.

This is a problem on for example Apple iMac14,1 all-in-ones where
the monitor's LCD panel shows up as a regular DP connection instead of
eDP so the GPU driver will not call acpi_video_register_backlight() [1].

Fix this by making video.ko directly register the acpi_video# devices
when these have been explicitly requested either on the cmdline or
through DMI quirks (rather then auto-detection being used).

[1] GPU drivers only call acpi_video_register_backlight() when an internal
panel is detected, to avoid non working acpi_video# devices getting
registered on desktops which unfortunately is a real issue.

Fixes: 5aa9d943e9b6 ("ACPI: video: Don't enable fallback path for creating ACPI backlight by default")
Cc: All applicable <stable@vger.kernel.org>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Don't enable fallback path for creating ACPI backlight by default

The ACPI video detection code has a module parameter
`register_backlight_delay` which is currently configured to 8 seconds.
This means that if after 8 seconds of booting no native driver has created
a backlight device then the code will attempt to make an ACPI video
backlight device.

This was intended as a safety mechanism with the backlight overhaul that
occurred in kernel 6.1, but as it doesn't appear necesssary set it to be
disabled by default.

Suggested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Allow GPU drivers to report no panels

The current logic for the ACPI backlight detection will create
a backlight device if no native or vendor drivers have created
8 seconds after the system has booted if the ACPI tables
included backlight control methods.

If the GPU drivers have loaded, they may be able to report whether
any LCD panels were found. Allow using this information to factor
in whether to enable the fallback logic for making an acpi_video0
backlight device.

Suggested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: make remove callback of ACPI driver void

For bus-based driver, device removal is implemented as:
1 device_remove()->
2 bus->remove()->
3 driver->remove()

Driver core needs no inform from callee(bus driver) about the
result of remove callback. In that case, commit fc7a6209d571
("bus: Make remove callback return void") forces bus_type::remove
be void-returned.

Now we have the situation that both 1 & 2 of calling chain are
void-returned, so it does not make much sense for 3(driver->remove)
to return non-void to its caller.

So the basic idea behind this change is making remove() callback of
any bus-based driver to be void-returned.

This change, for itself, is for device drivers based on acpi-bus.

Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Lee Jones <lee@kernel.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dawei Li <set_pte_at@outlook.com>
Reviewed-by: Maximilian Luz <luzmaximilian@gmail.com> # for drivers/platform/surface/*
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Change disable_backlight_sysfs_if quirks to acpi_backlight=native

Some Toshibas have a broken acpi-video interface for brightness control
and need a special firmware call on resume to turn the panel back on.
So far these have been using the disable_backlight_sysfs_if workaround
to deal with this.

The recent x86/acpi backlight refactoring has broken this workaround:
1. This workaround relies on acpi_video_get_backlight_type() returning
acpi_video so that the acpi_video code actually runs; and
2. this relies on the actual native GPU driver to offer the sysfs
backlight interface to userspace.

After the refactor this breaks since the native driver will no
longer register its backlight-device if acpi_video_get_backlight_type()
does not return native and making it return native breaks 1.

Keeping the acpi_video backlight handling on resume active, while not
using it to set the brightness, is necessary because it does a _BCM
call on resume which is necessary to turn the panel back on on resume.

Looking at the DSDT shows that this _BCM call results in a Toshiba
HCI_SET HCI_LCD_BRIGHTNESS call, which turns the panel back on.

This kind of special vendor specific handling really belongs in
the vendor specific acpi driver. An earlier patch in this series
modifies toshiba_acpi to make the necessary HCI_SET call on resume
on affected models.

With toshiba_acpi taking care of the HCI_SET call on resume,
the acpi_video code no longer needs to call _BCM on resume.

So instead of using the (now broken) disable_backlight_sysfs_if
workaround, simply setting acpi_backlight=native to disable
the broken apci-video interface is sufficient fix things now.

After this there are no more users of the disable_backlight_sysfs_if
flag and as discussed above the flag also no longer works as intended,
so remove the disable_backlight_sysfs_if flag entirely.

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Arvid Norlander <lkml@vorpal.se>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

ACPI: video: Remove acpi_video_set_dmi_backlight_type()

acpi_video_set_dmi_backlight_type() is troublesome because it may end
up getting called after other backlight drivers have already called
acpi_video_get_backlight_type() resulting in the other drivers
already being registered even though they should not.

In case of the acpi_video backlight, acpi_video_set_dmi_backlight_type()
actually calls acpi_video_unregister_backlight() since that is often
probed earlier, leading to userspace seeing the acpi_video0 class
device being briefly available, leading to races in userspace where
udev probe-rules try to access the device and it is already gone.

All callers have been fixed to no longer call it, so remove
acpi_video_set_dmi_backlight_type() now.

This means we now also no longer need acpi_video_unregister_backlight()
for the remove acpi_video backlight after it was wrongly registered hack,
so remove that too.

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

ACPI: video: Remove code to unregister acpi_video backlight when a native backlight registers

Remove the code to unregister acpi_video backlight devices when
a native backlight device gets registered later.

Now that the acpi_video backlight device registration is a separate step
which runs later, after the drm/kms driver is done setting up its own
native backlight device, it is no longer necessary to monitor for a
native (BACKLIGHT_RAW) device showing up later and to then unregister
the acpi_video backlight device(s).

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

ACPI: video: Make backlight class device registration a separate step (v2)

On x86/ACPI boards the acpi_video driver will usually initialize before
the kms driver (except i915). This causes /sys/class/backlight/acpi_video0
to show up and then the kms driver registers its own native backlight
device after which the drivers/acpi/video_detect.c code unregisters
the acpi_video0 device (when acpi_video_get_backlight_type()==native).

This means that userspace briefly sees 2 devices and the disappearing of
acpi_video0 after a brief time confuses the systemd backlight level
save/restore code, see e.g.:
https://bbs.archlinux.org/viewtopic.php?id=269920

To fix this make backlight class device registration a separate step
done by a new acpi_video_register_backlight() function. The intend is for
this to be called by the drm/kms driver *after* it is done setting up its
own native backlight device. So that acpi_video_get_backlight_type() knows
if a native backlight will be available or not at acpi_video backlight
registration time, avoiding the add + remove dance.

Note the new acpi_video_register_backlight() function is also called from
a delayed work to ensure that the acpi_video backlight devices does get
registered if necessary even if there is no drm/kms driver or when it is
disabled.

Changes in v2:
- Make register_backlight_delay a module parameter, mainly so that it can
be disabled by Nvidia binary driver users

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

ACPI: video: Simplify acpi_video_unregister_backlight()

When acpi_video_register() has not run yet the video_bus_head will be
empty, so there is no need to check the register_count flag first.

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

ACPI: video: Remove acpi_video_bus from list before tearing it down

Move the list_del removing an acpi_video_bus from video_bus_head
on teardown to before the teardown is done, to avoid code iterating
over the video_bus_head list seeing acpi_video_bus objects on there
which are (partly) torn down already.

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

ACPI: video: Add Toshiba Satellite/Portege Z830 quirk

Toshiba Satellite Z830 needs the quirk video_disable_backlight_sysfs_if
for proper backlight control after suspend/resume cycles.

Toshiba Portege Z830 is simply the same laptop rebranded for certain
markets (I looked through the manual to other language sections to confirm
this) and thus also needs this quirk.

Thanks to Hans de Goede for suggesting this fix.

Link: https://www.spinics.net/lists/platform-driver-x86/msg34394.html
Suggested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Arvid Norlander <lkml@vorpal.se>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Arvid Norlander <lkml@vorpal.se>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: Drop parent field from struct acpi_device

The parent field in struct acpi_device is, in fact, redundant,
because the dev.parent field in it effectively points to the same
object and it is used by the driver core.

Accordingly, the parent field can be dropped from struct acpi_device
and for this purpose define acpi_dev_parent() to retrieve a parent
struct acpi_device pointer from the dev.parent field in struct
acpi_device. Next, update all of the users of the parent field
in struct acpi_device to use acpi_dev_parent() instead of it and
drop it.

While at it, drop the ACPI_IS_ROOT_DEVICE() macro that is only used
in one place in a confusing way.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Punit Agrawal <punit.agrawal@bytedance.com>

ACPI: video: Fix acpi_video_handles_brightness_key_presses()

Commit 3a0cf7ab8df3 ("ACPI: video: Change how we determine if brightness
key-presses are handled") made acpi_video_handles_brightness_key_presses()
report false when none of the ACPI Video Devices support backlight control.

But it turns out that at least on a Dell Inspiron N4010 there is no ACPI
backlight control, yet brightness hotkeys are still reported through
the ACPI Video Bus; and since acpi_video_handles_brightness_key_presses()
now returns false, brightness keypresses are now reported twice.

To fix this rename the has_backlight flag to may_report_brightness_keys and
also set it the first time a brightness key press event is received.

Depending on the delivery of the other ACPI (WMI) event vs the ACPI Video
Bus event this means that the first brightness key press might still get
reported twice, but all further keypresses will be filtered as before.

Note that this relies on other drivers reporting brightness key events
calling acpi_video_handles_brightness_key_presses() when delivering
the events (rather then once during driver probe). This is already
required and documented in include/acpi/video.h:

/*
* Note: The value returned by acpi_video_handles_brightness_key_presses()
* may change over time and should not be cached.
*/

Fixes: 3a0cf7ab8df3 ("ACPI: video: Change how we determine if brightness key-presses are handled")
Link: https://lore.kernel.org/regressions/CALF=6jEe5G8+r1Wo0vvz4GjNQQhdkLT5p8uCHn6ZXhg4nsOWow@mail.gmail.com/
Reported-and-tested-by: Ben Greening <bgreening@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220713211101.85547-2-hdegoede@redhat.com

ACPI: video: Change how we determine if brightness key-presses are handled

Some systems have an ACPI video bus but not ACPI video devices with
backlight capability. On these devices brightness key-presses are
(logically) not reported through the ACPI video bus.

Change how acpi_video_handles_brightness_key_presses() determines if
brightness key-presses are handled by the ACPI video driver to avoid
vendor specific drivers/platform/x86 drivers filtering out their
brightness key-presses even though they are the only ones reporting
these presses.

Fixes: ed83c9171829 ("platform/x86: panasonic-laptop: Resolve hotkey double trigger bug")
Reported-and-tested-by: Stefan Seyfried <seife+kernel@b1-systems.com>
Reported-and-tested-by: Kenneth Chan <kenneth.t.chan@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220624112340.10130-2-hdegoede@redhat.com

ACPI: video: Use acpi_dev_for_each_child()

Instead of walking the list of children of an ACPI device directly,
use acpi_dev_for_each_child() to carry out an action for all of
the given ACPI device's children.

This will help to eliminate the children list head from struct
acpi_device as it is redundant and it is used in questionable ways
in some places (in particular, locking is needed for walking the
list pointed to it safely, but it is often missing).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

ACPI: video: Fix acpi_video_handles_brightness_key_presses()

Commit 3a0cf7ab8df3 ("ACPI: video: Change how we determine if brightness
key-presses are handled") made acpi_video_handles_brightness_key_presses()
report false when none of the ACPI Video Devices support backlight control.

But it turns out that at least on a Dell Inspiron N4010 there is no ACPI
backlight control, yet brightness hotkeys are still reported through
the ACPI Video Bus; and since acpi_video_handles_brightness_key_presses()
now returns false, brightness keypresses are now reported twice.

To fix this rename the has_backlight flag to may_report_brightness_keys and
also set it the first time a brightness key press event is received.

Depending on the delivery of the other ACPI (WMI) event vs the ACPI Video
Bus event this means that the first brightness key press might still get
reported twice, but all further keypresses will be filtered as before.

Note that this relies on other drivers reporting brightness key events
calling acpi_video_handles_brightness_key_presses() when delivering
the events (rather then once during driver probe). This is already
required and documented in include/acpi/video.h:

/*
* Note: The value returned by acpi_video_handles_brightness_key_presses()
* may change over time and should not be cached.
*/

Fixes: 3a0cf7ab8df3 ("ACPI: video: Change how we determine if brightness key-presses are handled")
Link: https://lore.kernel.org/regressions/CALF=6jEe5G8+r1Wo0vvz4GjNQQhdkLT5p8uCHn6ZXhg4nsOWow@mail.gmail.com/
Reported-and-tested-by: Ben Greening <bgreening@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220713211101.85547-2-hdegoede@redhat.com

ACPI: video: Change how we determine if brightness key-presses are handled

Some systems have an ACPI video bus but not ACPI video devices with
backlight capability. On these devices brightness key-presses are
(logically) not reported through the ACPI video bus.

Change how acpi_video_handles_brightness_key_presses() determines if
brightness key-presses are handled by the ACPI video driver to avoid
vendor specific drivers/platform/x86 drivers filtering out their
brightness key-presses even though they are the only ones reporting
these presses.

Fixes: ed83c9171829 ("platform/x86: panasonic-laptop: Resolve hotkey double trigger bug")
Reported-and-tested-by: Stefan Seyfried <seife+kernel@b1-systems.com>
Reported-and-tested-by: Kenneth Chan <kenneth.t.chan@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220624112340.10130-2-hdegoede@redhat.com

ACPI: video: improve PM notifer callback

PM notifier callbacks should check for supported events rather than filter
out the unsupported events. So that it won't break when a new event is
introduced.

No functional change in this patch.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: Use acpi_fetch_acpi_dev() instead of acpi_bus_get_device()

Modify the ACPI code to use acpi_fetch_acpi_dev() instead of
acpi_bus_get_device() where applicable.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

ACPI: video: Add quirk for the Dell Vostro 3350

The Dell Vostro 3350 ACPI video-bus device reports spurious
ACPI_VIDEO_NOTIFY_CYCLE events resulting in spurious KEY_SWITCHVIDEOMODE
events being reported to userspace (and causing trouble there).

Add a quirk setting the report_key_events mask to
REPORT_BRIGHTNESS_KEY_EVENTS so that the ACPI_VIDEO_NOTIFY_CYCLE
events will be ignored, while still reporting brightness up/down
hotkey-presses to userspace normally.

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1911763
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Drop three redundant return statements

Signed-off-by: Clayton Casciato <majortomtosourcecontrol@gmail.com>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Check LCD flag on ACPI-reduced-hardware devices

Starting with Windows 8, Windows no longer uses the ACPI-video interface
for backlight control by default. Instead backlight control is left up
to the GPU drivers and these are typically directly accessing the GPU
for this instead of going through ACPI.

This means that the ACPI video interface is no longer being tested by
many vendors, which leads to false-positive /sys/class/backlight entries
on devices which don't have a backlight at all such as desktops or
top-set boxes. These false-positives causes desktop environments to show
a non functional brightness slider in various places.

Checking the LCD flag greatly reduces the amount of false-positives,
so commit 5928c281524f ("ACPI / video: Default lcd_only to true on
Win8-ready and newer machines") enabled the checking of this flag
by default on all win8 BIOS-es. But this let to regressions on some
models, so the check was made stricter adding a DMI chassis-type check
to only enable the LCD flag checking on desktop/server chassis.

Unfortunately the chassis-type reported in the DMI strings is not always
reliable. One class of devices where this is a problem is Intel Bay Trail-T
based top-set boxes / mini PCs / HDMI sticks. These are based on reference
designs which were targetets and the reference design BIOS code
is often used without changing the chassis-type to something more
appropriate.

There are many, many Bay Trail-T based devices affected by this, so DMI
quirking our way out of this is a bad idea. This patch takes a different
approach, Bay Trail-T (unlike regular Bay Trail) is an ACPI-reduced-hw
platform and ACPI-reduced-hw platforms generally don't have
an embedded-controller and thus will use a native (GPU specific) backlight
interface. This patch enables Checking the LCD flag by default on
ACPI-reduced-hw platforms with a win8 BIOS independent of the reported
chassis-type, fixing the false positive /sys/class/backlight entries
on these devices.

Note in hindsight I should have never added the DMI chassis-type check
when the enabling of LCD flag checking on Windows 8 BIOS-es let to some
regressions. Instead I should have added DMI quirks for the (presumably
few) models where the LCD flag check let to issues. But I'm afraid that
it is too late to change this now, changing this now will likely lead to
a bunch of regressions.

This patch was tested on a Mele PCG03 mini PC.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: fix various typos in comments

Fix trivial ACPI driver comment typos.

s/notifcations/notifications/
s/Ajust/Adjust/
s/preform/perform/
s/atrributes/attributes/
s/Souce/Source/
s/Evalutes/Evaluates/
s/Evalutes/Evaluates/
s/specifiy/specify/
s/promixity/proximity/
s/presuambly/presumably/
s/Evalute/Evaluate/
s/specificed/specified/
s/rountine/routine/
s/previosuly/previously/

Change comment referencing pcc_send_cmd to send_pcc_cmd.

Signed-off-by: Tom Saeger <tom.saeger@oracle.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Clean up printing messages

Replace the ACPI_DEBUG_PRINT() instances in acpi_video.c with
acpi_handle_debug() calls and the ACPI_EXCEPTION()/ACPI_ERROR()/
ACPI_WARNING() instances in there with acpi_handle_info() calls,
which among other things causes the excessive log levels of those
messages to be increased.

Drop the _COMPONENT and ACPI_MODULE_NAME() definitions that are not
used any more from acpi_video.c, drop the no longer needed
ACPI_VIDEO_COMPONENT definition from the headers and update the
documentation accordingly.

While at it, add a pr_fmt() definition to acpi_video.c, replace the
direct printk() invocations in there with acpi_handle_info() or
pr_info() (and reduce the excessive log level where applicable) and
drop the PREFIX sybmbol definition which is not necessary any more
from acpi_video.c.

Also make unrelated janitorial changes to fix up white space and
use ACPI_FAILURE() instead of negating ACPI_SUCCESS().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

ACPI: Fix whitespace inconsistencies

Replaces spaces with tabs where spaces have been (inconsistently) used
for indentation and removes trailing whitespaces.

Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: remove redundant assignments to variable result

The variable result is being initialized with a value that is never
read and it is being updated later with a new value. The initialization
is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: fix typo in comment

Signed-off-by: Kacper Piwiński <cosiekvfj@o2.pl>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: update doc for acpi_video_bus_DOS()

Commit efaa14c:

"Starting from win8, MS backlight control driver will set bit 2 of the
parameter of control method _DOS, to inform firmware it should not
perform any automatic brightness changes. This mostly affects hotkey
notification deliver - if we do not set this bit, on hotkey press,
firmware may choose to adjust brightness level instead of sending out
notification and doing nothing."

win7:
https://download.microsoft.com/download/9/c/5/9c5b2167-8017-4bae-9fde-d599bac8184a/BrightnessCtrl.docx

"To avoid problems that might occur if both the system firmware and
the monitor driver control the brightness of the display, the display
miniport driver should set bit 2 of the argument to the _DOS method.
Setting this bit notifies the system firmware that it should not
perform any automatic display brightness changes. The WDDM
driver must set this particular bit because it controls the _DOS
method. The other bits in the _DOS method control the behavior of
the firmware in response to the display switch hot keys."

win8:
http://read.pudn.com/downloads193/doc/907411/Brightness.doc

Signed-off-by: Kacper Piwiński <cosiekvfj@o2.pl>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: video: Add new hw_changes_brightness quirk, set it on PB Easynote MZ35

Some machines change the brightness themselves when a brightness hotkey
gets pressed, despite us telling them not to. This causes the brightness to
go two steps up / down when the hotkey is pressed. This is esp. a problem
on older machines with only a few brightness levels.

This commit adds a new hw_changes_brightness quirk which makes
acpi_video_device_notify() only call backlight_force_update(...,
BACKLIGHT_UPDATE_HOTKEY) and not do anything else, notifying userspace
that the brightness was changed and leaving it at that fixing the dual
step problem.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=204077
Reported-by: Kacper Piwiński <cosiekvfj@o2.pl>
Tested-by: Kacper Piwiński <cosiekvfj@o2.pl>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157

Based on 3 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [kishon] [vijay] [abraham]
[i] [kishon]@[ti] [com] this program is distributed in the hope that
it will be useful but without any warranty without even the implied
warranty of merchantability or fitness for a particular purpose see
the gnu general public license for more details

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version [author] [graeme] [gregory]
[gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
[kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
[hk] [hemahk]@[ti] [com] this program is distributed in the hope
that it will be useful but without any warranty without even the
implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ACPI / video: Extend chassis-type detection with a "Lunch Box" check

Commit 53fa1f6e8a59 ("ACPI / video: Only default only_lcd to true on
Win8-ready _desktops_") introduced chassis type detection, limiting the
lcd_only check for the backlight to devices where the chassis-type
indicates their is no builtin LCD panel.

The purpose of the lcd_only check is to avoid advertising a backlight
interface on desktops, since skylake and newer machines seem to always
have a backlight interface even if there is no LCD panel. The limiting
of this check to desktops only was done to avoid breaking backlight
support on some laptops which do not have the lcd flag set.

The Fujitsu ESPRIMO Q910 which is a compact (NUC like) desktop machine
has a chassis type of 0x10 aka "Lunch Box". Without the lcd_only check
we end up falsely advertising backlight/brightness control on this
device. This commit extend the dmi_is_desktop check to return true
for type 0x10 to fix this.

Fixes: 53fa1f6e8a59 ("ACPI / video: Only default only_lcd to true ...")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Refactor and fix dmi_is_desktop()

This commit refactors the chassis-type detection introduced by
commit 53fa1f6e8a59 ("ACPI / video: Only default only_lcd to true on
Win8-ready _desktops_") (where desktop means anything without a builtin
screen).

The DMI chassis_type is an unsigned integer, so rather then doing a
whole bunch of string-compares on it, convert it to an int and feed
the result to a switch case.

Note the switch case uses hex values, this is done because the spec
uses hex values too. This changes the check for "Main Server Chassis"
from checking for 11 decimal to 11 hexadecimal, this is a bug fix,
the original check for 11 decimal was wrong.

Fixes: 53fa1f6e8a59 ("ACPI / video: Only default only_lcd to true ...")
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
[ rjw: Drop redundant return statements ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

treewide: kmalloc() -> kmalloc_array()

The kmalloc() function has a 2-factor argument form, kmalloc_array(). This
patch replaces cases of:

kmalloc(a * b, gfp)

with:
kmalloc_array(a * b, gfp)

as well as handling cases of:

kmalloc(a * b * c, gfp)

with:

kmalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kmalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kmalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The tools/ directory was manually excluded, since it has its own
implementation of kmalloc().

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kmalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kmalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kmalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kmalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kmalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kmalloc
+ kmalloc_array
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kmalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kmalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kmalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kmalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kmalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kmalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kmalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kmalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kmalloc(C1 * C2 * C3, ...)
|
kmalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kmalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kmalloc(sizeof(THING) * C2, ...)
|
kmalloc(sizeof(TYPE) * C2, ...)
|
kmalloc(C1 * C2 * C3, ...)
|
kmalloc(C1 * C2, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kmalloc
+ kmalloc_array
(
- (E1) * E2
+ E1, E2
, ...)
|
- kmalloc
+ kmalloc_array
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kmalloc
+ kmalloc_array
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>

ACPI / video: Only default only_lcd to true on Win8-ready _desktops_

Commit 5928c281524f (ACPI / video: Default lcd_only to true on Win8-ready
and newer machines) made only_lcd default to true on all machines where
acpi_osi_is_win8() returns true, including laptops.

The purpose of this is to avoid the bogus / non-working acpi backlight
interface which many newer BIOS-es define on desktop machines.

But this is causing a regression on some laptops, specifically on the
Dell XPS 13 2013 model, which does not have the LCD flag set for its
fully functional ACPI backlight interface.

Rather then DMI quirking our way out of this, this commits changes the
logic for setting only_lcd to true, to only do this on machines with
a desktop (or server) dmi chassis-type.

Note that we cannot simply only check the chassis-type and not register
the backlight interface based on that as there are some laptops and
tablets which have their chassis-type set to "3" aka desktop. Hopefully
the combination of checking the LCD flag, but only on devices with
a desktop(ish) chassis-type will avoid the needs for DMI quirks for this,
or at least limit the amount of DMI quirks which we need to a minimum.

Fixes: 5928c281524f (ACPI / video: Default lcd_only to true on Win8-ready and newer machines)
Reported-and-tested-by: James Hogan <jhogan@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Cc: 4.15+ <stable@vger.kernel.org> # 4.15+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Use true for boolean value

Assign true or false to boolean variables instead of an integer value.

This issue was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Default lcd_only to true on Win8-ready and newer machines

We're seeing a lot of bogus backlight interfaces on newer machines without
a LCD such as desktops, servers and HDMI sticks. This causes userspace to
show a non-functional brightness slider in e.g. the GNOME3 system menu,
which is undesirable. And, in general, we should simply just not register
a non functional backlight interface.

Checking the LCD flag causes the bogus acpi_video backlight interfaces to
go away (on the machines this was tested on).

This change sets the lcd_only option by default on any machines which
are Win8-ready, to fix this.

This is not entirely without a risk of regressions, but video_detect.c
already prefers native-backlight interfaces over the acpi_video one
on Win8-ready machines, calling acpi_video_unregister_backlight() as soon
as a native interface shows up. This is done because the ACPI backlight
interface often is broken on Win8-ready machines, because win8 does not
seem to actually use it.

So in practice we already end up not registering the ACPI backlight
interface on (most) Win8-ready machines with a LCD panel, thus this
change does not change anything for (most) machines with a LCD panel
and on machines without a LCD panel we actually don't want to register
any backlight interfaces.

This has been tested on the following machines and fixes a bogus backlight
interface showing up there:
- Desktop with an Asrock B150M Pro4S/D3 m.b. using i5-6500 builtin gfx
- Intel Compute Stick STK1AW32SC
- Meegopad T08 HDMI stick

Bogus backlight interfaces have also been reported on:
- Desktop with Asus H87I-Plus m.b.
- Desktop with ASRock B75M-ITX m.b.
- Desktop with Gigabyte Z87-D3HP m.b.
- Dell PowerEdge T20 desktop

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1097436
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1133327
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1133329
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1133646
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

dmi: Mark all struct dmi_system_id instances const

... and __initconst if applicable.

Based on similar work for an older kernel in the Grsecurity patch.

[JD: fix toshiba-wmi build]
[JD: add htcpen]
[JD: move __initconst where checkscript wants it]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jean Delvare <jdelvare@suse.de>

ACPI / video: add comments about subtle cases

The comment for acpi_video_bqc_quirk is by Felipe Contreras, taken from
the git history.

Signed-off-by: Dmitry Frank <mail@dmitryfrank.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: get rid of magic numbers and use enum instead

The first two items in the _BCL method response are special:

- Level when machine has full power
- Level when machine is on batteries
- .... actual supported levels go there ....

So this commits adds an enum and uses its descriptive elements
throughout the code, instead of magic numbers.

Signed-off-by: Dmitry Frank <mail@dmitryfrank.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Replace <asm/uaccess.h> with <linux/uaccess.h> globally

This was entirely automated, using the script by Al:

PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ACPI / video: Move ACPI_VIDEO_NOTIFY_* defines to acpi/video.h

acpi_video.c passed the ACPI_VIDEO_NOTIFY_* defines as type code to
acpi_notifier_call_chain(). Move these defines to acpi/video.h so
that acpi_notifier listeners can check the type code using these
defines.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Peter Wu <peter@lekensteyn.nl>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: skip evaluating _DOD when it does not exist

Some system supports hybrid graphics and its discrete VGA
does not have any connectors and therefore has no _DOD method.

Signed-off-by: Alex Hung <alex.hung@canonical.com>
Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / Thermal / video: fix max_level incorrect value

commit 059500940def (ACPI/video: export acpi_video_get_levels)
mistakenly dropped the correct value of max_level and that caused the
set_level function following failed and the acpi_video backlight interface
didn't get created. Fix this by passing back the correct max_level value.

While at it, also fix the param used in acpi_video_device_lcd_query_levels
where acpi_handle is expected but acpi_video_device is passed.

Fixes: 059500940def (ACPI/video: export acpi_video_get_levels)
Reported-and-tested-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI/video: export acpi_video_get_levels

The acpi_video_get_levels is useful for other drivers, i.e. the
to-be-added int3406 thermal driver, so export it.

Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: remove unused device_decode array

device_decode is now no longer used, so we may as well remove it.
Fixes gcc 6 warning:

drivers/acpi/acpi_video.c:221:19: warning: ‘device_decode’ defined
but not used [-Wunused-const-variable]
static const char device_decode[][30] = {
^~~~~~~~~~~~~

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Add disable_backlight_sysfs_if quirk for the Toshiba Satellite R830

The Toshiba Satellite R830 needs disable_backlight_sysfs_if=1, just like
the Toshiba Portege R830. Add a quirk for this.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=21012
Cc: 4.2+ <stable@vger.kernel.org> # 4.2+
Tested-by: To Do <entodoays@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Fix using an uninitialized mutex / list_head in acpi_video_handles_brightness_key_presses()

If acpi_video_handles_brightness_key_presses() was called before
acpi_video_register(), it would use the video_list mutex / list_head
uninitialized.

This patch fixes this by using DEFINE_MUTEX / LIST_HEAD when declaring
these, instead of initializing them runtime from acpi_video_register().

Fixes: 90b066b15eda "ACPI / video: Add a acpi_video_handles_brightness_key_presses() helper"
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Revert "ACPI / video: driver must be registered before checking for keypresses"

On systems with an intel video opcode region, the completion used in the
patch this commit reverts will only complete if the i915 driver loads.

If for some reason the i915 driver never loads calls to
acpi_video_handles_brightness_key_presses() may be delayed indefinitely.

This reverts commit aecbd9b1bff6 ("ACPI / video: driver must be registered
before checking for keypresses") fixing this.

This reintroduces a potential NULL pointer deref due to using an
uninitalized mutex, this is fixed differently in a follow-up patch.

Fixes: aecbd9b1bff6 (ACPI / video: driver must be registered before checking for keypresses)
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Add disable_backlight_sysfs_if quirk for the Toshiba Portege R700

The Toshiba Portege R700 needs disable_backlight_sysfs_if=1, just like
the Toshiba Portege R830. Add a quirk for this.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=21012
Cc: 4.2+ <stable@vger.kernel.org> # 4.2+
Tested-by: Emma Reisz <emmareisz@outlook.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: driver must be registered before checking for keypresses

acpi_video_handles_brightness_key_presses() may use an uninitialized mutex.
The error has been reported by lockdep: DEBUG_LOCKS_WARN_ON(l->magic != l).
The function assumes that the video driver has been registered before being
called. As explained in the comment of acpi_video_init(), the registration
of the video class may be defered and thus may not take place in the init
function of the module.

Use completion mechanisms to make sure that
acpi_video_handles_brightness_key_presses() wait for the completion of
acpi_video_register() before using the mutex.
Also get rid of register_count since task completion can replace it.

Signed-off-by: Adrien Schildknecht <adrien+dev@schischi.me>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Add quirks for the Dell Vostro V131

The Dell Vostro V131 has an especially broken acpi-video implementation.

The backlight control bits work, but when the brightness is changed via
the acpi-video interface the backlight flickers annoyingly before settling
at the new brightness, switching to using the native interface fixes the
flickering so add a quirk for this (the vendor interface has the same
problem).

Brightness keypresses reported through the acpi-video-bus are also broken,
they get reported one event delayed, so if you press the brightness-up
hotkey on the keyboard nothing happens, then if you press brightness-down,
the previous brightness-up event gets reported. Since the keypresses are
also reported via wmi (if active) and via atkbd (when wmi is not active)
add a quirk to simply filter out the delayed (broken) events.

Reported-and-tested-by: Michał Kępień <kernel@kempniu.pl>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Add a module option to disable the reporting of keypresses

Add a module option to disable the reporting of keypresses, in some buggy
firmware implementatinon, the reported events are wrong. E.g. they lag
reality by one event in the case triggering the writing of this patch.

In this case it is better to not forward these wrong events to userspace
(esp.) when there is another source of the same events which is not buggy.

Note this is only intended to work around implementations which send
events which are plain wrong. In some cases we get double events, e.g.
from both acpi-video and the atkbd driver, in this case acpi-video is
considered the canonical source, and the events from the other source
should be filtered (using e.g. /lib/udev/hwdb.d/60-keyboard.hwdb).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Add a acpi_video_handles_brightness_key_presses() helper

Several drivers want to know if the acpi-video is generating key-presses
for brightness change hotkeys to avoid sending double key-events to
userspace for these. Currently these driver use this construct for this:

if (acpi_video_get_backlight_type() == acpi_backlight_vendor)
report_brightness_key_event();

This indirect way of detecting if acpi-video is active does not make the
code easier to understand, and in some cases it is wrong because just
because the preferred type != vendor does not mean that acpi-video is
actually listening for brightness events, e.g. there may be no acpi-video
bus on the system at all.

This commit adds a acpi_video_handles_brightness_key_presses() helper
function, making the code needing this functionality both easier to read
and more correct.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: only register backlight for LCD device

The firmware of ESPRIMO Mobile M9410 has two video output devices that
have _BCM control method, one is the type of "External Digital Monitor"
while the other is the type of "Internal/Integrated Digital Flat Panel".
Only the 2nd video output device's _BCM control method works, but
since we have created two and the 1st one got picked up by user space,
the backlight functionality is broken. To solve this problem, only
register backlight interface for "Internal/Integrated Digital Flat Panel"
type video output device on this laptop.

Another problem of this laptop is that the IDs listed by the _DOD method
doesn't have bit 31 set, which means it doesn't follow the format
specified by ACPI spec. But the value indicates that it actually follows
that format so I've added a DMI quirk and a module level parameter to
force use the device_id_scheme so that we can get the video output
device's type to do the decision if we should register backlight
interface.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=104121
Suggested-by: Hans de Goede <hdegoede@redhat.com>
Reported-and-tested-by: Christian Scharl <zahlsum-kernelbugs@yahoo.de>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI: Remove FSF mailing addresses

There is no need to carry potentially outdated Free Software Foundation
mailing address in file headers since the COPYING file includes it.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Make acpi_video_unregister_backlight() private

acpi_video_unregister_backlight() is now only used by video_detect.c
which is part of the same acpi_video module as video.c, make
acpi_video_unregister_backlight() private to this module.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Fix acpi_video _register vs _unregister_backlight race

It is possible for a native backlight driver to load while
acpi_video_register is running, which may lead to
acpi_video_unregister_backlight being called while acpi_video_register
is running and the 2 racing against eachother.

The register_count variable protects against this, but not in a thread
safe manner, this commit adds locking to make this thread safe.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Move dmi_check_system from module_init to acpi_video_register

When builtin there is no guarantee in which order module_init functions
are run, so acpi_video_register() may get called from the i915 driver
(if it is also builtin) before acpi_video_init() gets called, resulting
in the dmi quirks not yet being parsed.

This commit moves the dmi_check_system() call to acpi_video_register(),
so that we can be sure the dmi quirks have always been applied before
probing.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Move backlight notifier to video_detect.c

Move the unregistering of the acpi backlight interface on registering of a
native backlight from video.c to video_detect.c where it belongs.

Note this removes support for re-registering the acpi backlight interface
when the native interface goes away. In practice this never happens and
it needlessly complicates the code.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / video: Port to new backlight interface selection API

Most of the patch is moving the dmi quirks for forcing use of the
acpi-video / the native backlight interface to video_detect.c.

What remains is a nice cleanup.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

acpi-video-detect: video: Make video_detect code part of the video module

This is a preparation patch for the backlight interface selection logic
cleanup, there are 2 reasons to not always build the video_detect code
into the kernel:

1) In order for the video_detect.c to also deal with / select native
backlight interfaces on win8 systems, instead of doing this in video.c
where it does not belong, video_detect.c needs to call into the backlight
class code. Which cannot be done if it is builtin and the blacklight class
is not.

2) Currently all the platform/x86 drivers which have quirks to prefer
the vendor driver over acpi-video call acpi_video_unregister_backlight()
to remove the acpi-video backlight interface, this logic really belongs
in video_detect.c, which will cause video_detect.c to depend on symbols of
video.c and video.c already depends on video_detect.c symbols, so they
really need to be a single module.

Note that this commits make 2 changes so as to maintain 100% kernel
commandline compatibility:

1) The __setup call for the acpi_backlight= handling is moved to
acpi/util.c as __setup may only be used by code which is alwasy builtin
2) video.c is renamed to acpi_video.c so that it can be combined with
video_detect.c into video.ko

This commit also makes changes to drivers/platform/x86/Kconfig to ensure
that drivers which use acpi_video_backlight_support() from video_detect.c,
will not be built-in when acpi_video is not built in. This also changes
some "select" uses to "depends on" to avoid dependency loops.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>