usb: Disable USB3 LPM at shutdown

SanDisks USB3 storage may disapper after system reboot:

usb usb2-port3: link state change
xhci_hcd 0000:00:14.0: clear port3 link state change, portsc: 0x2c0
usb usb2-port3: do warm reset, port only
xhci_hcd 0000:00:14.0: xhci_hub_status_data: stopping usb2 port polling
xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x2b0, return 0x2b0
usb usb2-port3: not warm reset yet, waiting 50ms
xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x2f0, return 0x2f0
usb usb2-port3: not warm reset yet, waiting 200ms
...
xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x6802c0, return 0x7002c0
usb usb2-port3: not warm reset yet, waiting 200ms
xhci_hcd 0000:00:14.0: clear port3 reset change, portsc: 0x4802c0
xhci_hcd 0000:00:14.0: clear port3 warm(BH) reset change, portsc: 0x4002c0
xhci_hcd 0000:00:14.0: clear port3 link state change, portsc: 0x2c0
xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x2c0, return 0x2c0
usb usb2-port3: not enabled, trying warm reset again...

This is due to the USB device still cause port change event after xHCI is
shuted down:

xhci_hcd 0000:38:00.0: // Setting command ring address to 0xffffe001
xhci_hcd 0000:38:00.0: xhci_resume: starting usb3 port polling.
xhci_hcd 0000:38:00.0: xhci_hub_status_data: stopping usb4 port polling
xhci_hcd 0000:38:00.0: xhci_hub_status_data: stopping usb3 port polling
xhci_hcd 0000:38:00.0: hcd_pci_runtime_resume: 0
xhci_hcd 0000:38:00.0: xhci_shutdown: stopping usb3 port polling.
xhci_hcd 0000:38:00.0: // Halt the HC
xhci_hcd 0000:38:00.0: xhci_shutdown completed - status = 1
xhci_hcd 0000:00:14.0: xhci_shutdown: stopping usb1 port polling.
xhci_hcd 0000:00:14.0: // Halt the HC
xhci_hcd 0000:00:14.0: xhci_shutdown completed - status = 1
xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x1203, return 0x203
xhci_hcd 0000:00:14.0: set port reset, actual port 2-3 status = 0x1311
xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x201203, return 0x100203
xhci_hcd 0000:00:14.0: clear port3 reset change, portsc: 0x1203
xhci_hcd 0000:00:14.0: clear port3 warm(BH) reset change, portsc: 0x1203
xhci_hcd 0000:00:14.0: clear port3 link state change, portsc: 0x1203
xhci_hcd 0000:00:14.0: clear port3 connect change, portsc: 0x1203
xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x1203, return 0x203
usb 2-3: device not accepting address 2, error -108
xhci_hcd 0000:00:14.0: xHCI dying or halted, can't queue_command
xhci_hcd 0000:00:14.0: Set port 2-3 link state, portsc: 0x1203, write 0x11261
xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x1263, return 0x263
xhci_hcd 0000:00:14.0: set port reset, actual port 2-3 status = 0x1271
xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x12b1, return 0x2b1
usb usb2-port3: not reset yet, waiting 60ms
ACPI: PM: Preparing to enter system sleep state S5
xhci_hcd 0000:00:14.0: Get port status 2-3 read: 0x12f1, return 0x2f1
usb usb2-port3: not reset yet, waiting 200ms
reboot: Restarting system

The port change event is caused by LPM transition, so disabling LPM at shutdown
to make sure the device is in U0 for warmboot.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20240305065140.66801-1-kai.heng.feng@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: core: Fix deadlock in port "disable" sysfs attribute

The show and store callback routines for the "disable" sysfs attribute
file in port.c acquire the device lock for the port's parent hub
device. This can cause problems if another process has locked the hub
to remove it or change its configuration:

Removing the hub or changing its configuration requires the
hub interface to be removed, which requires the port device
to be removed, and device_del() waits until all outstanding
sysfs attribute callbacks for the ports have returned. The
lock can't be released until then.

But the disable_show() or disable_store() routine can't return
until after it has acquired the lock.

The resulting deadlock can be avoided by calling
sysfs_break_active_protection(). This will cause the sysfs core not
to wait for the attribute's callback routine to return, allowing the
removal to proceed. The disadvantage is that after making this call,
there is no guarantee that the hub structure won't be deallocated at
any moment. To prevent this, we have to acquire a reference to it
first by calling hub_get().

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/f7a8c135-a495-4ce6-bd49-405a45e7ea9a@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: core: Set connect_type of ports based on DT node

When a USB hub is described in DT, such as any device that matches the
onboard-hub driver, the connect_type is set to "unknown" or
USB_PORT_CONNECT_TYPE_UNKNOWN. This makes any device plugged into that
USB port report their 'removable' device attribute as "unknown".
ChromeOS userspace would like to know if the USB device is actually
removable or not so that security policies can be applied. Improve the
connect_type attribute for ports, and in turn the removable attribute
for USB devices, by looking for child devices with a reg property or an
OF graph when the device is described in DT.

If the graph exists, endpoints that are connected to a remote node must
be something like a usb-{a,b,c}-connector compatible node, or an
intermediate node like a redriver, and not a hardwired USB device on the
board. Set the connect_type to USB_PORT_CONNECT_TYPE_HOT_PLUG in this
case because the device is going to be plugged in. Set the connect_type
to USB_PORT_CONNECT_TYPE_HARD_WIRED if there's a child node for the port
like 'device@2' for port2. Set the connect_type to USB_PORT_NOT_USED if
there isn't an endpoint or child node corresponding to the port number.

To make sure things don't change, only set the port to not used if
there are child nodes. This way an onboard hub connect_type doesn't
change until ports are added or child nodes are added to describe
hardwired devices. It's assumed that all ports or no ports will be
described for a device.

Cc: Matthias Kaehlcke <mka@chromium.org>
Cc: linux-usb@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: Pin-yen Lin <treapking@chromium.org>
Cc: maciek swiech <drmasquatch@google.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20240223005823.3074029-3-swboyd@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: core: constify the struct device_type usage

Since commit aed65af1cc2f ("drivers: make device_type const"), the driver
core can properly handle constant struct device_type. Move the
usb_device_type, usb_if_device_type, usb_ep_device_type and
usb_port_device_type variables to be constant structures as well, placing
it into read-only memory which can not be modified at runtime.

Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Link: https://lore.kernel.org/r/20240218-device_cleanup-usb-v1-4-77423c4da262@marliere.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: port: Don't try to peer unused USB ports based on location

Unused USB ports may have bogus location data in ACPI PLD tables.
This causes port peering failures as these unused USB2 and USB3 ports
location may match.

Due to these failures the driver prints a
"usb: port power management may be unreliable" warning, and
unnecessarily blocks port power off during runtime suspend.

This was debugged on a couple DELL systems where the unused ports
all returned zeroes in their location data.
Similar bugreports exist for other systems.

Don't try to peer or match ports that have connect type set to
USB_PORT_NOT_USED.

Fixes: 3bfd659baec8 ("usb: find internal hub tier mismatch via acpi")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218465
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218486
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de>
Link: https://lore.kernel.org/linux-usb/5406d361-f5b7-4309-b0e6-8c94408f7d75@molgen.mpg.de
Cc: stable@vger.kernel.org # v3.16+
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218490
Link: https://lore.kernel.org/r/20240222233343.71856-1-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: core: Remove duplicated check in usb_hub_create_port_device

Simplify the code by not calling hub_is_superspeed() twice.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/b1d77cbc-faa3-4d07-94ff-f6ffb85c6964@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: Inform the USB Type-C class about enumerated devices

The Type-C port drivers can make PM related decisions based
on is the device USB3 or USB2.

Suggested-by: Benson Leung <bleung@chromium.org>
Tested-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20231011105825.320062-3-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: core: add sysfs entry for usb device state

Expose usb device state to userland as the information is useful in
detecting non-compliant setups and diagnosing enumeration failures.
For example:
- End-to-end signal integrity issues: the device would fail port reset
repeatedly and thus be stuck in POWERED state.
- Charge-only cables (missing D+/D- lines): the device would never enter
POWERED state as the HC would not see any pullup.

What's the status quo?
We do have error logs such as "Cannot enable. Maybe the USB cable is bad?"
to flag potential setup issues, but there's no good way to expose them to
userspace.

Why add a sysfs entry in struct usb_port instead of struct usb_device?
The struct usb_device is not device_add() to the system until it's in
ADDRESS state hence we would miss the first two states. The struct
usb_port is a better place to keep the information because its life
cycle is longer than the struct usb_device that is attached to the port.

Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202306042228.e532af6e-oliver.sang@intel.com
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Roy Luo <royluo@google.com>
Message-ID: <20230608015913.1679984-1-royluo@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: core: stop USB enumeration if too many retries

When a broken USB accessory connects to a USB host, usbcore might
keep doing enumeration retries. If the host has a watchdog mechanism,
the kernel panic will happen on the host.

This patch provides an attribute early_stop to limit the numbers of retries
for each port of a hub. If a port was marked with early_stop attribute,
unsuccessful connection attempts will fail quickly. In addition, if an
early_stop port has failed to initialize, it will ignore all future
connection events until early_stop attribute is clear.

Signed-off-by: Ray Chi <raychi@google.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20221107072754.3336357-1-raychi@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: core: Use kstrtobool() instead of strtobool()

strtobool() is the same as kstrtobool().
However, the latter is more used within the kernel.

In order to remove strtobool() and slightly simplify kstrtox.h, switch to
the other function name.

While at it, include the corresponding header file (<linux/kstrtox.h>)

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/f01ef2ddaf12a6412127611617786adc1234e0b4.1667336095.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: hub: port: add sysfs entry to switch port power

In some cases the port of an hub needs to be disabled or switched off
and on again. E.g. when the connected device needs to be re-enumerated.
Or it needs to be explicitly disabled while the rest of the usb tree
stays working.

For this purpose this patch adds an sysfs switch to enable/disable the
port on any hub. In the case the hub is supporting power switching, the
power line will be disabled to the connected device.

When the port gets disabled, the associated device gets disconnected and
removed from the logical usb tree. No further device will be enumerated
on that port until the port gets enabled again.

Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20220607114522.3359148-1-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: core: Unregister device on component_add() failure

Commit 8c67d06f3fd9 ("usb: Link the ports to the connectors they are
attached to") creates a link to the USB Type-C connector for every new
port that is added when possible. If component_add() fails,
usb_hub_create_port_device() prints a warning but does not unregister
the device and does not return errors to the callers.

Syzbot reported a "WARNING in component_del()".

Fix this issue in usb_hub_create_port_device by calling device_unregister()
and returning the errors from component_add().

Fixes: 8c67d06f3fd9 ("usb: Link the ports to the connectors they are attached to")
Reported-and-tested-by: syzbot+60df062e1c41940cae0f@syzkaller.appspotmail.com
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Link: https://lore.kernel.org/r/20220209164500.8769-1-fmdefrancesco@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: Link the ports to the connectors they are attached to

Creating link to the USB Type-C connector for every new port
that is added when possible.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20211223082349.45616-1-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "usb: Link the ports to the connectors they are attached to"

This reverts commit 63cd78617350dae99cc5fbd8f643b83ee819fe33 as it
causes a build error:
depmod: ERROR: Cycle detected: usbcore -> typec -> usbcore
depmod: ERROR: Found 2 modules in dependency cycles!

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lore.kernel.org/r/20210412213655.3776e15e@canb.auug.org.au
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: Link the ports to the connectors they are attached to

Creating link to the USB Type-C connector for every new port
that is added when possible.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20210407065555.88110-3-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: core: Constify static attribute_group structs

These are never modified, so make them const to allow the compiler to
put them in read-only memory. Done with the help of coccinelle.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Link: https://lore.kernel.org/r/20201125162500.37228-2-rikard.falkeborn@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: core: port: do error out if usb_autopm_get_interface() fails

Reviewing a fresh portion of coverity defects in USB core
(specifically CID 1458999), Alan Stern noted below in [1]:

On Tue, Feb 25, 2020 at 02:39:23PM -0500, Alan Stern wrote:
> A revised search finds line 997 in drivers/usb/core/hub.c and lines
> 216, 269 in drivers/usb/core/port.c. (I didn't try looking in any
> other directories.) AFAICT all three of these should check the
> return value, although a error message in the kernel log probably
> isn't needed.

Factor out the usb_port_runtime_{resume,suspend}() changes into a
standalone patch to allow conflict-free porting on top of stable v3.9+.

[1] https://lore.kernel.org/lkml/Pine.LNX.4.44L0.2002251419120.1485-100000@iolanthe.rowland.org

Fixes: 971fcd492cebf5 ("usb: add runtime pm support for usb port device")
Cc: stable@vger.kernel.org # v3.9+
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20200226175036.14946-3-erosca@de.adit-jv.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: Disable USB2 LPM at shutdown

The QCA Rome USB Bluetooth controller has several issues once LPM gets
enabled:
- Fails to get enumerated in coldboot. [1]
- Drains more power (~ 0.2W) when the system is in S5. [2]
- Disappears after a warmboot. [2]

The issue happens because the device lingers at LPM L1 in S5, so device
can't get enumerated even after a reboot.

Disable LPM at shutdown to solve the issue.

[1] https://bugs.launchpad.net/bugs/1757218
[2] https://patchwork.kernel.org/patch/10607097/

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Link: https://lore.kernel.org/r/20190805142412.23965-1-kai.heng.feng@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: export firmware port location in sysfs

The platform firmware "location" data is used to find port peer
relationships. But firmware is an unreliable source, and there are
real world examples of errors leading to missing or wrong peer
relationships. Debugging this is currently hard.

Exporting the location attribute makes it easier to spot mismatches
between the firmware data and the real world.

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: hub: Per-port setting to use old enumeration scheme

The "old" enumeration scheme is considerably faster (it takes
~244ms instead of ~356ms to get the descriptor).

It is currently only possible to use the old scheme globally
(/sys/module/usbcore/parameters/old_scheme_first), which is not
desirable as the new scheme was introduced to increase compatibility
with more devices.

However, in our case, we care about time-to-active for a specific
USB device (which we make the firmware for), on a specific port
(that is pogo-pin based: not a standard USB port). This new
sysfs option makes it possible to use the old scheme on a single
port only.

Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: core: introduce per-port over-current counters

For some userspace applications information on the number of
over-current conditions at specific USB hub ports is relevant.

In our case we have a series of USB hardware (using the cp210x driver)
which communicates using a proprietary protocol. These devices sometimes
trigger an over-current situation on some hubs. In case of such an
over-current situation the USB devices offer an interface for reducing
the max used power. As these conditions are quite rare and imply
performance reductions of the device we don't want to reduce the max
power always.

Therefore give user-space applications the possibility to react
adequately by introducing an over_current_counter in the usb port struct
which is exported via sysfs.

Signed-off-by: Richard Leitner <richard.leitner@skidata.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: core: Remove redundant license text

Now that the SPDX tag is in all USB files, that identifies the license
in a specific and legally-defined manner. So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: add SPDX identifiers to all remaining files in drivers/usb/

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "USB / PM: Allow USB devices to remain runtime-suspended when sleeping"

This reverts commit e3345db85068ddb937fc0ba40dfc39c293dad977, which
broke system resume for a large class of devices.

Devices that after having been reset during resume need to be rebound
due to a missing reset_resume callback, are now left in a suspended
state. This specifically broke resume of common USB-serial devices,
which are now unusable after system suspend (until disconnected and
reconnected) when USB persist is enabled.

During resume, usb_resume_interface will set the needs_binding flag for
such interfaces, but unlike system resume, run-time resume does not
honour it.

Cc: stable <stable@vger.kernel.org> # 4.5
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB / PM: Allow USB devices to remain runtime-suspended when sleeping

Have dev_pm_ops.prepare return 1 for USB devices and ports so that USB
devices can remain runtime-suspended when the system goes to a sleep
state, if their wakeup state is correct and they have runtime PM enabled.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

usb: Quiet down false peer failure messages

My recent Intel box is spewing these messages:

xhci_hcd 0000:00:14.0: xHCI Host Controller
xhci_hcd 0000:00:14.0: new USB bus registered, assigned bus number 2
usb usb2: New USB device found, idVendor=1d6b, idProduct=0003
usb usb2: New USB device strings: Mfr=3, Product=2, SerialNumber=1
usb usb2: Product: xHCI Host Controller
usb usb2: Manufacturer: Linux 4.3.0+ xhci-hcd
usb usb2: SerialNumber: 0000:00:14.0
hub 2-0:1.0: USB hub found
hub 2-0:1.0: 6 ports detected
usb: failed to peer usb2-port2 and usb1-port1 by location (usb2-port2:none) (usb1-port1:usb2-port1)
usb usb2-port2: failed to peer to usb1-port1 (-16)
usb: port power management may be unreliable
usb: failed to peer usb2-port3 and usb1-port1 by location (usb2-port3:none) (usb1-port1:usb2-port1)
usb usb2-port3: failed to peer to usb1-port1 (-16)
usb: failed to peer usb2-port5 and usb1-port1 by location (usb2-port5:none) (usb1-port1:usb2-port1)
usb usb2-port5: failed to peer to usb1-port1 (-16)
usb: failed to peer usb2-port6 and usb1-port1 by location (usb2-port6:none) (usb1-port1:usb2-port1)
usb usb2-port6: failed to peer to usb1-port1 (-16)

Diving into the acpi tables, I noticed the EHCI hub has 12 ports while the XHCI
hub has 8 ports. Most of those ports are of connect type USB_PORT_NOT_USED
(including port 1 of the EHCI hub).

Further the unused ports have location data initialized to 0x80000000.

Now each unused port on the xhci hub walks the port list and finds a matching
peer with port1 of the EHCI hub because the zero'd out group id bits falsely match.
After port1 of the XHCI hub, each following matching peer will generate the
above warning.

These warnings seem to be harmless for this scenario as I don't think it
matters that unused ports could not create a peer link.

The attached patch utilizes that assumption and just turns the pr_warn into
pr_debug to quiet things down.

Tested on my Intel box.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: core: lpm: add sysfs node for usb3 lpm permit

USB3 LPM is default on in Linux kernel if both xHCI host controller
and the USB devices declare to be LPM-capable. Unfortunately, some
devices are known to work well with LPM disabled, but to be broken
if LPM is enabled, although it declares the LPM capability. Users
won't be able to use this kind of devices, until someone puts them
in the kernel blacklist and gets the kernel upgraded.

This patch adds a sysfs node to permit or forbit USB3 LPM U1 or U2
entry for a port. The settings apply to both before and after device
enumeration. Supported values are "0" - neither u1 nor u2 permitted,
"u1" - only u1 is permitted, "u2" - only u2 is permitted, "u1_u2" -
both u1 and u2 are permitted. With this interface, users can use an
LPM-unfriendly USB device on a released Linux kernel.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Zhuang Jin Can <jin.can.zhuang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB / PM: Drop CONFIG_PM_RUNTIME from the USB core

After commit b2b49ccbdd54 (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so quite a few
depend on CONFIG_PM (or even dropped in some cases).

Replace CONFIG_PM_RUNTIME with CONFIG_PM in the USB core code
and documentation.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: force warm reset to break link re-connect livelock

Resuming a powered down port sometimes results in the port state being
stuck in the training sequence.

hub 3-0:1.0: debounce: port 1: total 2000ms stable 0ms status 0x2e0
port1: can't get reconnection after setting port power on, status -110
hub 3-0:1.0: port 1 status 0000.02e0 after resume, -19
usb 3-1: can't resume, status -19
hub 3-0:1.0: logical disconnect on port 1

In the case above we wait for the port re-connect timeout of 2 seconds
and observe that the port status is USB_SS_PORT_LS_POLLING (although it
is likely toggling between this state and USB_SS_PORT_LS_RX_DETECT).
This is indicative of a case where the device is failing to progress the
link training state machine.

It is resolved by issuing a warm reset to get the hub and device link
state machines back in sync.

hub 3-0:1.0: debounce: port 1: total 2000ms stable 0ms status 0x2e0
usb usb3: port1 usb_port_runtime_resume requires warm reset
hub 3-0:1.0: port 1 not warm reset yet, waiting 50ms
usb 3-1: reset SuperSpeed USB device number 2 using xhci_hcd

After a reconnect timeout when we expect the device to be present, force
a warm reset of the device. Note that we can not simply look at the
link status to determine if a warm reset is required as any of the
training states USB_SS_PORT_LS_POLLING, USB_SS_PORT_LS_RX_DETECT, or
USB_SS_PORT_LS_COMP_MOD are valid states that do not indicate the need
for warm reset by themselves.

Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Vincent Palatin <vpalatin@chromium.org>
Cc: Lan Tianyu <tianyu.lan@intel.com>
Cc: Ksenia Ragiadakou <burzalodowa@gmail.com>
Cc: Vivek Gautam <gautam.vivek@samsung.com>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Sunil Joshi <joshi@samsung.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Acked-by: Julius Werner <jwerner@chromium.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: fix hub-port pm_runtime_enable() vs runtime pm transitions

Commit 9262c19d14c4 "usb: disable port power control if not supported in
wHubCharacteristics" gated enabling runtime pm for usb_port devices on
whether the parent hub supports power control, which causes a
regression. The port must still be allowed to carry out runtime pm
callbacks and receive a -EAGAIN or -EBUSY result. Otherwise the
usb_port device will transition to the pm error state and trigger the
same for the child usb_device.

Prior to the offending commit usb_hub_create_port_device() arranged for
runtime pm to be disabled is dev_pm_qos_expose_flags() failed. Instead,
force the default state of PM_QOS_FLAG_NO_POWER_OFF flag to be set prior
to enabling runtime pm. If that policy can not be set then fail
registration.

Report: http://marc.info/?l=linux-usb&m=140290586301336&w=2
Fixes: 9262c19d14c4 ("usb: disable port power control if not supported in wHubCharacteristics")
Reported-by: Bjørn Mork <bjorn@mork.no>
Reported-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: quiet peer failure warning, disable poweroff

In the case where platform firmware has specified conflicting values for
port locations it is confusing and otherwise not helpful to throw a
backtrace. Instead, include enough information to determine that
firmware has done something wrong and globally disable port poweroff.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: resume child device when port is powered on

Unconditionally wake up the child device when the power session is
recovered.

This addresses the following scenarios:

1/ The device may need a reset on power-session loss, without this
change port power-on recovery exposes khubd to scenarios that
usb_port_resume() is set to handle. Prior to port power control the
only time a power session would be lost is during dpm_suspend of the
hub. In that scenario usb_port_resume() is guaranteed to be called
prior to khubd running for that port. With this change we wakeup the
child device as soon as possible (prior to khubd running again for this
port).

Although khubd has facilities to wake a child device it will only do
so if the portstatus / portchange indicates a suspend state. In the
case of port power control we are not coming from a hub-port-suspend
state. This implementation simply uses pm_request_resume() to wake the
device and relies on the port_dev->status_lock to prevent any collisions
between khubd and usb_port_resume().

2/ This mechanism rate limits port power toggling. The minimum port
power on/off period is now gated by the child device suspend/resume
latency. Empirically this mitigates devices downgrading their connection
on perceived instability of the host connection. This ratelimiting is
really only relevant to port power control testing, but it is a nice
side effect of closing the above race. Namely, the race of khubd for
the given port running while a usb_port_resume() event is pending.

3/ Going forward we are finding that power-session recovery requires
warm-resets (http://marc.info/?t=138659232900003&r=1&w=2). This
mechanism allows for warm-resets to be requested at the same point in
the resume path for hub dpm_suspend power session losses, or port
rpm_suspend power session losses.

4/ If the device *was* disconnected the only time we'll know for sure is
after a failed resume, so it's necessary for usb_port_runtime_resume()
to expedite a usb_port_resume() to clean up the removed device. The
reasoning for this is "least surprise" for the user. Turning on a port
means that hotplug detection is again enabled for the port, it is
surprising that devices that were removed while the port was off are not
disconnected until they are attempted to be used. As a user "why would
I try to use a device I removed from the system?"

1, 2, and 4 are not a problem in the system dpm_resume() case because,
although the power-session is lost, khubd is frozen until after device
resume. For the rpm_resume() case pm_request_resume() is used to
request re-validation of the device, and if it happens to collide with a
khubd run we rely on the port_dev->status_lock to synchronize those
operations.

Besides testing, the primary scenario where this mechanism is expected
to be triggered is when the user changes the port power policy
(control/pm_qos_no_poweroff, or power/control). Each time power is
enabled want to revalidate the child device, where the revalidation is
handled by usb_port_resume().

Given that this arranges for port_dev->child to be de-referenced in
usb_port_runtime_resume() we need to make sure not to collide with
usb_disconnect() that frees the usb_device. To this end we hold the
port active with the "child_usage" reference across the disconnect
event. Subsequently, the need to access hub->child_usage_bits lead to
the creation of hub_disconnect_children() to remove any ambiguity of
which "hub" is being acted on in usb_disconnect() (prompted-by sharp
eyes from Alan).

Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: introduce port status lock

In general we do not want khubd to act on port status changes that are
the result of in progress resets or USB runtime PM operations.
Specifically port power control testing has been able to trigger an
unintended disconnect in hub_port_connect_change(), paraphrasing:

if ((portstatus & USB_PORT_STAT_CONNECTION) && udev &&
udev->state != USB_STATE_NOTATTACHED) {
if (portstatus & USB_PORT_STAT_ENABLE) {
/* Nothing to do */
} else if (udev->state == USB_STATE_SUSPENDED &&
udev->persist_enabled) {
...
} else {
/* Don't resuscitate */;
}
}

...by falling to the "Don't resuscitate" path or missing
USB_PORT_STAT_CONNECTION because usb_port_resume() was in the middle of
modifying the port status.

So, we want a new lock to hold off khubd for a given port while the
child device is being suspended, resumed, or reset. The lock ordering
rules are now usb_lock_device() => usb_lock_port(). This is mandated by
the device core which may hold the device_lock on the usb_device before
invoking usb_port_{suspend|resume} which in turn take the status_lock on
the usb_port. We attempt to hold the status_lock for the duration of a
port_event() run, and drop/re-acquire it when needing to take the
device_lock. The lock is also dropped/re-acquired during
hub_port_reconnect().

This patch also deletes hub->busy_bits as all use cases are now covered
by port PM runtime synchronization or the port->status_lock and it
pushes down usb_device_lock() into usb_remote_wakeup().

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: usb3 ports do not support FEAT_C_ENABLE

The port pm_runtime implementation unconditionally clears FEAT_C_ENABLE
after clearing PORT_POWER, but the bit is reserved on usb3 hub ports.
We expect khubd to be prevented from running because the port state is
not RPM_ACTIVE, so we need to clear any errors for usb2 ports.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: don't clear FEAT_C_ENABLE on usb_port_runtime_resume failure

Three reasons:
1/ It's an invalid operation on usb3 ports
2/ There's no guarantee of when / if a usb2 port has entered an error
state relative to PORT_POWER request
3/ The port is active / powered at this point, so khubd will clear it as
a matter of course

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: block suspension of superspeed port while hispeed peer is active

ClearPortFeature(PORT_POWER) on a usb3 port places the port in either a
DSPORT.Powered-off-detect / DSPORT.Powered-off-reset loop, or the
DSPORT.Powered-off state. There is no way to ensure that RX
terminations will persist in this state, so it is possible a device will
degrade to its usb2 connection. Prevent this by blocking power-off of a
usb3 port while its usb2 peer is active, and powering on a usb3 port
before its usb2 peer.

By default the latency between peer power-on events is 0. In order for
the device to not see usb2 active while usb3 is still powering up inject
the hub recommended power_on_good delay. In support of satisfying the
power_on_good delay outside of hub_power_on() refactor the places where
the delay is consumed to call a new hub_power_on_good_delay() helper.

Finally, because this introduces several new checks for whether a port
is_superspeed, cache that disctinction at port creation so that we don't
need to keep looking up the parent hub device.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
[alan]: add a 'superspeed' flag to the port
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: make usb_port flags atomic, rename did_runtime_put to child_usage

We want to manipulate ->did_runtime_put in usb_port_runtime_resume(),
but we don't want that to collide with other updates. Move usb_port
flags to new port-bitmap fields in usb_hub. "did_runtime_put" is renamed
"child_usage_bits" to reflect that it is strictly standing in for the
fact that usb_devices are not the device_model children of their parent
port.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: sysfs link peer ports

The usb topology after this change will have symlinks between usb3 ports
and their usb2 peers, for example:

usb2/2-1/2-1:1.0/2-1-port1/peer => ../../../../usb3/3-1/3-1:1.0/3-1-port1
usb2/2-1/2-1:1.0/2-1-port2/peer => ../../../../usb3/3-1/3-1:1.0/3-1-port2
usb2/2-1/2-1:1.0/2-1-port3/peer => ../../../../usb3/3-1/3-1:1.0/3-1-port3
usb2/2-1/2-1:1.0/2-1-port4/peer => ../../../../usb3/3-1/3-1:1.0/3-1-port4
usb2/2-0:1.0/usb2-port1/peer => ../../../usb3/3-0:1.0/usb3-port1
usb2/2-0:1.0/usb2-port2/peer => ../../../usb3/3-0:1.0/usb3-port2
usb2/2-0:1.0/usb2-port3/peer => ../../../usb3/3-0:1.0/usb3-port3
usb2/2-0:1.0/usb2-port4/peer => ../../../usb3/3-0:1.0/usb3-port4

usb3/3-1/3-1:1.0/usb3-1-port1/peer => ../../../../usb2/2-1/2-1:1.0/2-1-port1
usb3/3-1/3-1:1.0/usb3-1-port2/peer => ../../../../usb2/2-1/2-1:1.0/2-1-port2
usb3/3-1/3-1:1.0/usb3-1-port3/peer => ../../../../usb2/2-1/2-1:1.0/2-1-port3
usb3/3-1/3-1:1.0/usb3-1-port4/peer => ../../../../usb2/2-1/2-1:1.0/2-1-port4
usb3/3-0:1.0/usb3-port1/peer => ../../../usb2/2-0:1.0/usb2-port1
usb3/3-0:1.0/usb3-port2/peer => ../../../usb2/2-0:1.0/usb2-port2
usb3/3-0:1.0/usb3-port3/peer => ../../../usb2/2-0:1.0/usb2-port3
usb3/3-0:1.0/usb3-port4/peer => ../../../usb2/2-0:1.0/usb2-port4

Introduce link_peers_report() to notify on all link_peers() failure
cases.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: find internal hub tier mismatch via acpi

ACPI identifies peer ports by setting their 'group_token' and
'group_position' _PLD data to the same value. If a platform has tier
mismatch [1] , ACPI can override the default (USB3 defined) peer port
association for internal hubs. External hubs follow the default peer
association scheme.

Location data is cached as an opaque cookie in usb_port_location data.

Note that we only consider the group_token and group_position attributes
from the _PLD data as ACPI specifies that group_token is a unique
identifier.

When we find port location data for a port then we assume that the
firmware will also describe its peer port. This allows the
implementation to only ever set the peer once. This leads to a question
about what happens when a pm runtime event occurs while the peer
associations are still resolving. Since we only ever set the peer
information once, a USB3 port needs to be prevented from suspending
while its ->peer pointer is NULL (implemented in a subsequent patch).

There is always the possibility that firmware mis-identifies the ports,
but there is not much the kernel can do in that case.

[1]: xhci 1.1 appendix D figure 131
[2]: acpi 5 section 6.1.8

[alan]: don't do default peering when acpi data present
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: assign usb3 external hub port peers

Given that root hub port peers are already established, external hub peer
ports can be determined by traversing the device topology:

1/ ascend to the parent hub and find the upstream port_dev

2/ walk ->peer to find the peer port

3/ descend to the peer hub via ->child

4/ find the port with the matching port id

Note that this assumes the port labeling scheme required by the
specification [1].

[1]: usb3 3.1 section 10.3.3

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: assign default peer ports for root hubs

Assume that the peer of a superspeed port is the port with the same id
on the shared_hcd root hub. This identification scheme is required of
external hubs by the USB3 spec [1]. However, for root hubs, tier mismatch
may be in effect [2]. Tier mismatch can only be enumerated via platform
firmware. For now, simply perform the nominal association.

A new lock 'usb_port_peer_mutex' is introduced to synchronize port
device add/remove with peer lookups. It protects peering against
changes to hcd->shared_hcd, hcd->self.root_hub, hdev->maxchild, and
port_dev->child pointers.

[1]: usb 3.1 section 10.3.3
[2]: xhci 1.1 appendix D

Cc: Alan Stern <stern@rowland.harvard.edu>
[alan: usb_port_peer_mutex locking scheme]
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: rename usb_port device objects

The current port name "portX" is ambiguous. Before adding more port
messages rename ports to "<hub-device-name>-portX"

This is an ABI change, but the suspicion is that it will go unnoticed as
the port power control implementation has been broken since its
introduction. If however, someone was relying on the old name we can
add sysfs links from the old name to the new name.

Additionally, it unifies/simplifies port dev_printk messages and modifies
instances of:
dev_XXX(hub->intfdev, ..."port %d"...
dev_XXX(&hdev->dev, ..."port%d"...
into:
dev_XXX(&port_dev->dev, ...

Now that the names are unique usb_port devices it would be nice if they
could be included in /sys/bus/usb. However, it turns out that this
breaks 'lsusb -t'. For now, create a dummy port driver so that print
messages are prefixed "usb 1-1-port3" rather than the
subsystem-ambiguous " 1-1-port3".

Finally, it corrects an odd usage of sscanf("port%d") in usb-acpi.c.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: disable port power control if not supported in wHubCharacteristics

A hub indicates whether it supports per-port power control via the
wHubCharacteristics field in its descriptor. If it is not supported
a hub will still emulate ClearPortPower(PORT_POWER) requests by
stopping the link state machine. However, since this does not save
power do not bother suspending.

This also consolidates support checks into a
hub_is_port_power_switchable() helper.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: mutual exclusion for resetting a hub and power-managing a port

The USB core doesn't properly handle mutual exclusion between
resetting a hub and changing the power states of the hub's ports. We
need to avoid sending port-power requests to the hub while it is being
reset, because such requests cannot succeed.

This patch fixes the problem by keeping track of when a reset is in
progress. At such times, attempts to suspend (power-off) a port will
fail immediately with -EBUSY, and calls to usb_port_runtime_resume()
will update the power_is_on flag and return immediately. When the
reset is complete, hub_activate() will automatically restore each port
to the proper power state.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: core: be specific about attribute permissions

Instead of having to audit all sysfs attributes, to ensure we get them
right, use the default macros the driver core provides us (read-only,
read-write) to make the code simpler, and to prevent any mistakes from
ever happening.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: Don't fail port power resume on device disconnect.

Userspace can tell the kernel to power off any USB port, including ones
that are visible and connectible to users. When an attached USB device
goes into suspend, the port will be powered off if the
pm_qos_no_port_poweroff file for its port is set to 0, the device does
not have remote wakeup enabled, and the device is marked as persistent.

If the user disconnects the USB device while the port is powered off,
the current code does not handle that properly. If you disconnect a
device, and then run `lsusb -v -s` for the device, the device disconnect
does not get handled by the USB core. The runtime resume of the port
fails, because hub_port_debounce_be_connected() returns -ETIMEDOUT.

This means the port resume fails and khubd doesn't handle the USB device
disconnect. This leaves the device listed in lsusb, and the port's
runtime_status will be permanently marked as "error".

Fix this by ignoring the return value of hub_port_debounce_be_connected.
Users can disconnect USB devices while the ports are powered off, and we
must be able to handle that.

This patch should be backported to kernels as old as 3.9, that
contain the commit ad493e5e580546e6c3024b76a41535476da1546a "usb: add
usb port auto power off mechanism"

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Lan Tianyu <tianyu.lan@intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

usb: check usb_hub_to_struct_hub() return value

usb_hub_to_struct_hub() can return NULL in some unlikely cases.
Add checks where appropriate, or pass the hub pointer as an additional
argument if it's known to be valid.

The places it makes sense to check usb_hub_to_struct_hub()
are picked based on feedback from Alan Stern.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PM / Runtime: Rework the "runtime idle" helper routine

The "runtime idle" helper routine, rpm_idle(), currently ignores
return values from .runtime_idle() callbacks executed by it.
However, it turns out that many subsystems use
pm_generic_runtime_idle() which checks the return value of the
driver's callback and executes pm_runtime_suspend() for the device
unless that value is not 0. If that logic is moved to rpm_idle()
instead, pm_generic_runtime_idle() can be dropped and its users
will not need any .runtime_idle() callbacks any more.

Moreover, the PCI, SCSI, and SATA subsystems' .runtime_idle()
routines, pci_pm_runtime_idle(), scsi_runtime_idle(), and
ata_port_runtime_idle(), respectively, as well as a few drivers'
ones may be simplified if rpm_idle() calls rpm_suspend() after 0 has
been returned by the .runtime_idle() callback executed by it.

To reduce overall code bloat, make the changes described above.

Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Kevin Hilman <khilman@linaro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>

USB / PM: Don't try to hide PM QoS flags from usb_port_device_release()

Remove the call to dev_pm_qos_hide_flags(), added by commit 6e30d7cb
"usb: Add driver/usb/core/(port.c,hub.h) files", from
usb_port_device_release(), because (1) it is completely unnecessary
(the flags have been removed already by the PM core during the
unregistration of the device object) and (2) it triggers a NULL
pointer dereference in sysfs_find_dirent() (dev->kobj.sd is NULL at
this point).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: remove CONFIG_USB_SUSPEND option

This patch (as1675) removes the CONFIG_USB_SUSPEND option, essentially
replacing it everywhere with CONFIG_PM_RUNTIME (except for one place
in hub.c, where it is replaced with CONFIG_PM because the code needs
to be used in both runtime and system PM). The net result is code
shrinkage and simplification.

There's very little point in keeping CONFIG_USB_SUSPEND because almost
everybody enables it. The few that don't will find that the usbcore
module has gotten somewhat bigger and they will have to take active
measures if they want to prevent hubs from being runtime suspended.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Revert "usb: Register usb port's acpi power resources"

This reverts commit 88bb965ed711e8a5984e70208ebc901a6ff4141f.

The linux-next branch of linux-pm tree has replaced
acpi_power_resource_(un)register_device() with new routines.
Commit 88bb965 will cause conflict in the linux-next tree.
So revert it and this will not affect other functions. Will
send a new patch with new routines after 3.9 merge window.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: enable usb port device's async suspend.

This patch is to set power.async_suspend for usb port in order
to allow it to be suspended and resumed asynchronously during
system sleep transitions.

The power.async_suspend flag is also set for devices that don't have
suspend or resume callbacks, because otherwise they would make the
main suspend/resume thread wait for their "asynchronous" children
(during suspend) or parents (during resume), effectively negating the
possible gains from executing these devices' suspend and resume
callbacks asynchronously.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: expose usb port's pm qos flags to user space

This patch is to expose usb port's pm qos flags(pm_qos_no_power_off,
pm_qos_remote_wakeup) to user space. User can set pm_qos_no_power_off
flag to prohibit the port from being powered off.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: add usb port auto power off mechanism

This patch is to add usb port auto power off mechanism.
When usb device is suspending, usb core will suspend usb port and
usb port runtime pm callback will clear PORT_POWER feature to
power off port if all conditions were met. These conditions are
remote wakeup disable, pm qos NO_POWER_OFF flag clear and persist
enable. When it resumes, power on port again.

Add did_runtime_put in the struct usb_port to ensure
pm_runtime_get/put(portdev) to be called pairedly. Set did_runtime_put
to true when call pm_runtime_put(portdev) during suspending. The
pm_runtime_get(portdev) only will be called when did_runtime_put
is set to true during resuming. Set did_runtime_put to false after
calling pm_runtime_get(portdev).

Make clear_port_feature() and hdev_to_hub() as global symbol.
Rename clear_port_feature() to usb_clear_port_feature() and
hdev_to_hub() to usb_hub_to_struct_hub().

Extend hub_port_debounce() with the fuction of debouncing to
be connected. Add two wraps: hub_port_debounce_be_connected()
and hub_port_debouce_be_stable().

Increase HUB_DEBOUNCE_TIMEOUT to 2000 because some usb ssds
needs around 1.5 or more to make the hub port status to be
connected steadily after being powered off and powered on.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: add runtime pm support for usb port device

This patch is to add runtime pm callback for usb port device.
Set/clear PORT_POWER feature in the resume/suspend callback.
Add portnum for struct usb_port to record port number. Do
pm_rumtime_get_sync/put(portdev) when a device is plugged/unplugged
to prevent it from being powered off when it is active.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: Register usb port's acpi power resources

This patch is to register usb port's acpi power resources. Create
link between usb port device and its acpi power resource.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: Add "portX/connect_type" attribute to expose usb port's connect type

Some platforms provide usb port connect types through ACPI. This
patch is to add this new attribute to expose these information
to user space.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: fix compilation error and warning of driver/usb/core/port.c on arm and blackfin

This patch is to fix compilation error and warning on the arm and blackfin.
Add linux/slab.h head file to driver/usb/core/port.c. These are reported
from 0-DAY kernel build testing backend.

head: 6e30d7cba992d626c9d16b3873a7b90c700d0e95
commit: 6e30d7cba992d626c9d16b3873a7b90c700d0e95 [26/26] usb: Add driver/usb/core/(port.c,hub.h) files
config: make ARCH=arm at91_dt_defconfig

All error/warnings:

drivers/usb/core/port.c: In function 'usb_port_device_release':
>> drivers/usb/core/port.c:25:2: error: implicit declaration of function 'kfree' [-Werror=implicit-function-declaration]
drivers/usb/core/port.c: In function 'usb_hub_create_port_device':
>> drivers/usb/core/port.c:38:2: error: implicit declaration of function 'kzalloc' [-Werror=implicit-function-declaration]
>> drivers/usb/core/port.c:38:40: error: 'GFP_KERNEL' undeclared (first use in this function)
drivers/usb/core/port.c:38:40: note: each undeclared identifier is reported only once for each function it appears in
cc1: some warnings being treated as errors

head: 6e30d7cba992d626c9d16b3873a7b90c700d0e95
commit: 6e30d7cba992d626c9d16b3873a7b90c700d0e95 [26/26] usb: Add driver/usb/core/(port.c,hub.h) files
config: make ARCH=blackfin BF526-EZBRD_defconfig

All warnings:

drivers/usb/core/port.c: In function 'usb_port_device_release':
drivers/usb/core/port.c:25:2: error: implicit declaration of function 'kfree' [-Werror=implicit-function-declaration]
drivers/usb/core/port.c: In function 'usb_hub_create_port_device':
drivers/usb/core/port.c:38:2: error: implicit declaration of function 'kzalloc' [-Werror=implicit-function-declaration]
>> drivers/usb/core/port.c:38:11: warning: assignment makes pointer from integer without a cast [enabled by default]
cc1: some warnings being treated as errors

Reported-by: Fengguang Wu <wfg@linux.intel.com>
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: Add driver/usb/core/(port.c,hub.h) files

This patch is to create driver/usb/core/(port.c,hub.h) files and move usb
port related code into port.c.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>