While stress testing a usb controller using a bind/unbind looop, the
following error loop was observed.

usb 7-1.2: new low-speed USB device number 3 using xhci-hcd
usb 7-1.2: hub failed to enable device, error -108
usb 7-1-port2: cannot disable (err = -22)
usb 7-1-port2: couldn't allocate usb_device
usb 7-1-port2: cannot disable (err = -22)
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: activate --> -22
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: activate --> -22
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: activate --> -22
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: activate --> -22
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: activate --> -22
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: activate --> -22
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: activate --> -22
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: activate --> -22
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
hub 7-1:1.0: hub_ext_port_status failed (err = -22)
** 57 printk messages dropped ** hub 7-1:1.0: activate --> -22
** 82 printk messages dropped ** hub 7-1:1.0: hub_ext_port_status failed (err = -22)

This continues forever. After adding tracebacks into the code,
the call sequence leading to this is found to be as follows.

[<ffffffc0007fc8e0>] hub_activate+0x368/0x7b8
[<ffffffc0007fceb4>] hub_resume+0x2c/0x3c
[<ffffffc00080b3b8>] usb_resume_interface.isra.6+0x128/0x158
[<ffffffc00080b5d0>] usb_suspend_both+0x1e8/0x288
[<ffffffc00080c9c4>] usb_runtime_suspend+0x3c/0x98
[<ffffffc0007820a0>] __rpm_callback+0x48/0x7c
[<ffffffc00078217c>] rpm_callback+0xa8/0xd4
[<ffffffc000786234>] rpm_suspend+0x84/0x758
[<ffffffc000786ca4>] rpm_idle+0x2c8/0x498
[<ffffffc000786ed4>] __pm_runtime_idle+0x60/0xac
[<ffffffc00080eba8>] usb_autopm_put_interface+0x6c/0x7c
[<ffffffc000803798>] hub_event+0x10ac/0x12ac
[<ffffffc000249bb8>] process_one_work+0x390/0x6b8
[<ffffffc00024abcc>] worker_thread+0x480/0x610
[<ffffffc000251a80>] kthread+0x164/0x178
[<ffffffc0002045d0>] ret_from_fork+0x10/0x40

kick_hub_wq() is called from hub_activate() even after failures to
communicate with the hub. This results in an endless sequence of
hub event -> hub activate -> wq trigger -> hub event -> ...

Provide two solutions for the problem.

- Only trigger the hub event queue if communication with the hub
  is successful.
- After a suspend failure, only resume already suspended interfaces
  if the communication with the device is still possible.

Each of the changes fixes the observed problem. Use both to improve
robustness.
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some of the USB core files were missing explicit license information.
As all files in the kernel tree are implicitly licensed under the
GPLv2-only, be explicit in case someone get confused looking at
individual files by using the SPDX nomenclature.
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When a USB driver is bound to an interface (either through probing or
by claiming it) or is unbound from an interface, the USB core always
disables Link Power Management during the transition and then
re-enables it afterward.  The reason is because the driver might want
to prevent hub-initiated link power transitions, in which case the HCD
would have to recalculate the various LPM parameters.  This
recalculation takes place when LPM is re-enabled and the new
parameters are sent to the device and its parent hub.

However, if the driver does not want to prevent hub-initiated link
power transitions then none of this work is necessary.  The parameters
don't need to be recalculated, and LPM doesn't need to be disabled and
re-enabled.

It turns out that disabling and enabling LPM can be time-consuming,
enough so that it interferes with user programs that want to claim and
release interfaces rapidly via usbfs.  Since the usbfs kernel driver
doesn't set the disable_hub_initiated_lpm flag, we can speed things up
and get the user programs to work by leaving LPM alone whenever the
flag isn't set.

And while we're improving the way disable_hub_initiated_lpm gets used,
let's also fix its kerneldoc.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Tested-by: NMatthew Giassa <matthew@giassa.net>
CC: Mathias Nyman <mathias.nyman@intel.com>
CC: <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Attacks that trick drivers into passing a NULL pointer
to usb_driver_claim_interface() using forged descriptors are
known. This thwarts them by sanity checking.
Signed-off-by: NOliver Neukum <ONeukum@suse.com>
CC: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use kmalloc_array instead of kmalloc to allocate memory for an array.
Also, remove the dev_warn for a memory leak, making the if check more
sleek.
Signed-off-by: NMuhammad Falak R Wani <falakreyaz@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Driver probings and interface claims get rejected
if an interface is not authorized.
Signed-off-by: NStefan Koch <stefan.koch10@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit de7718bd as the
signed-off-by address is invalid.

Cc: Stefan Koch <stefan.koch10@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Driver probings and interface claims get rejected
if an interface is not authorized.
Signed-off-by: NStefan Koch <skoch@suse.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixed coding style issue: newline after declaration
Signed-off-by: NKris Borer <kborer@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Currently the USB stack assumes that all host controller drivers are
capable of receiving wakeup requests from downstream devices.
However, this isn't true for the isp1760-hcd driver, which means that
it isn't safe to do a runtime suspend of any device attached to a
root-hub port if the device requires wakeup.

This patch adds a "cant_recv_wakeups" flag to the usb_hcd structure
and sets the flag in isp1760-hcd.  The core is modified to prevent a
direct child of the root hub from being put into runtime suspend with
wakeup enabled if the flag is set.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Tested-by: NNicolas Pitre <nico@linaro.org>
CC: <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <greg@kroah.com>

The USB stack provides a mechanism for drivers to request an
asynchronous device reset (usb_queue_reset_device()).  The mechanism
uses a work item (reset_ws) embedded in the usb_interface structure
used by the driver, and the reset is carried out by a work queue
routine.

The asynchronous reset can race with driver unbinding.  When this
happens, we try to cancel the queued reset before unbinding the
driver, on the theory that the driver won't care about any resets once
it is unbound.

However, thanks to the fact that lockdep now tracks work queue
accesses, this can provoke a lockdep warning in situations where the
device reset causes another interface's driver to be unbound; see

	http://marc.info/?l=linux-usb&m=141893165203776&w=2

for an example.  The reason is that the work routine for reset_ws in
one interface calls cancel_queued_work() for the reset_ws in another
interface.  Lockdep thinks this might lead to a work routine trying to
cancel itself.  The simplest solution is not to cancel queued resets
when unbinding drivers.

This means we now need to acquire a reference to the usb_interface
when queuing a reset_ws work item and to drop the reference when the
work routine finishes.  We also need to make sure that the
usb_interface structure doesn't outlive its parent usb_device; this
means acquiring and dropping a reference when the interface is created
and destroyed.

In addition, cancelling a queued reset can fail (if the device is in
the middle of an earlier reset), and this can cause usb_reset_device()
to try to rebind an interface that has been deallocated (see
http://marc.info/?l=linux-usb&m=142175717016628&w=2 for details).
Acquiring the extra references prevents this failure.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-by: NRussell King - ARM Linux <linux@arm.linux.org.uk>
Reported-by: NOlivier Sobrie <olivier@sobrie.be>
Tested-by: NOlivier Sobrie <olivier@sobrie.be>
Cc: stable <stable@vger.kernel.org> # 3.19
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

After commit b2b49ccb (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: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When a host controller dies, we don't need to wait for a driver to
time out.  We can shut down its URBs immediately.  Without this
change, we can end up waiting 30 seconds for a mass-storage transfer
to time out.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Not all host controller drivers have bus-suspend and bus-resume
methods.  When one doesn't, it will cause problems if runtime PM is
enabled in the kernel.  The PM core will attempt to suspend the
controller's root hub, the suspend will fail because there is no
bus-suspend routine, and a -EBUSY error code will be returned to the
PM core.  This will cause the suspend attempt to be repeated shortly
thereafter, in a never-ending loop.

Part of the problem is that the original error code -ENOENT gets
changed to -EBUSY in usb_runtime_suspend(), on the grounds that the PM
core will interpret -ENOENT as meaning that the root hub has gotten
into a runtime-PM error state.  While this change is appropriate for
real USB devices, it's not such a good idea for a root hub.  In fact,
considering the root hub to be in a runtime-PM error state would not
be far from the truth.  Therefore this patch updates
usb_runtime_suspend() so that it adjusts error codes only for
non-root-hub devices.

Furthermore, the patch attempts to prevent the problem from occurring
in the first place by not enabling runtime PM by default for root hubs
whose host controller driver doesn't have bus_suspend and bus_resume
methods.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-by: NWill Deacon <will.deacon@arm.com>
Tested-by: NWill Deacon <will.deacon@arm.com>
CC: <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When a driver doesn't have pre_reset, post_reset, or reset_resume
methods, the USB core unbinds that driver when its device undergoes a
reset or a reset-resume, and then rebinds it afterward.

The existing straightforward implementation can lead to problems,
because each interface gets unbound and rebound before the next
interface is handled.  If a driver claims additional interfaces, the
claim may fail because the old binding instance may still own the
additional interface when the new instance tries to claim it.

This patch fixes the problem by first unbinding all the interfaces
that are marked (i.e., their needs_binding flag is set) and then
rebinding all of them.

The patch also makes the helper functions in driver.c a little more
uniform and adjusts some out-of-date comments.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: N"Poulain, Loic" <loic.poulain@intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/usb/bulk-streams.txt says:

All stream IDs will be deallocated when the driver releases the interface, to
ensure that drivers that don't support streams will be able to use the endpoint

This commit actually implements this.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

This modifies the probing order so that any matching
dynamic entry always will be used, even if the driver
has a matching static entry.

It is sometimes useful to dynamically update existing
device entries. With the new ability to set the dynamic
entry driver_info field, this can be used to test new
additions to class driver exception lists or proposed
changes to existing static per-device driver_info
entries.
Signed-off-by: NBjørn Mork <bjorn@mork.no>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix a memory leak in the usb_store_new_id() error paths. When bailing out
due to sanity checks, the function left the already allocated usb_dynid
struct in place. This regression was introduced by the following commits:

c63fe8f6 (usb: core: add sanity checks when using bInterfaceClass with new_id)
1b9fb31f (usb: core: check for valid id_table when using the RefId feature)
52a6966c (usb: core: bail out if user gives an unknown RefId when using new_id)

Detected by Coverity: CID 1162604.
Signed-off-by: NChristian Engelmayer <cengelma@gmx.at>
Acked-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When implementing the RefId feature, it was missed that id_tables can be
NULL under special circumstances. Bail out in that case.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If users use the new RefId feature of new_id, give them an error message
if they provided an unknown reference. That helps detecting typos.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Often, usb drivers need some driver_info to get a device to work. To
have access to driver_info when using new_id, allow to pass a reference
vendor:product tuple from which new_id will inherit driver_info.
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Check if that field is actually used and if so, bail out if it exeeds a
u8. Make it also future-proof by not requiring "exactly three"
parameters in new_id, but simply "more than two".
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

device_driver.name is "const char *"
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch changes a dev_warn() call in usbcore to dev_dbg().  It's
not necessary to warn about drivers missing a reset-resume callback,
since the reset-resume method is optional.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
CC: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

How it's supposed to work:
--------------------------

USB 2.0 Link PM is a lower power state that some newer USB 2.0 devices
support.  USB 3.0 devices certified by the USB-IF are required to
support it if they are plugged into a USB 2.0 only port, or a USB 2.0
cable is used.  USB 2.0 Link PM requires both a USB device and a host
controller that supports USB 2.0 hardware-enabled LPM.

USB 2.0 Link PM is designed to be enabled once by software, and the host
hardware handles transitions to the L1 state automatically.  The premise
of USB 2.0 Link PM is to be able to put the device into a lower power
link state when the bus is idle or the device NAKs USB IN transfers for
a specified amount of time.

...but hardware is broken:
--------------------------

It turns out many USB 3.0 devices claim to support USB 2.0 Link PM (by
setting the LPM bit in their USB 2.0 BOS descriptor), but they don't
actually implement it correctly.  This manifests as the USB device
refusing to respond to transfers when it is plugged into a USB 2.0 only
port under the Haswell-ULT/Lynx Point LP xHCI host.

These devices pass the xHCI driver's simple test to enable USB 2.0 Link
PM, wait for the port to enter L1, and then bring it back into L0.  They
only start to break when L1 entry is interleaved with transfers.

Some devices then fail to respond to the next control transfer (usually
a Set Configuration).  This results in devices never enumerating.

Other mass storage devices (such as a later model Western Digital My
Passport USB 3.0 hard drive) respond fine to going into L1 between
control transfers.  They ACK the entry, come out of L1 when the host
needs to send a control transfer, and respond properly to those control
transfers.  However, when the first READ10 SCSI command is sent, the
device NAKs the data phase while it's reading from the spinning disk.
Eventually, the host requests to put the link into L1, and the device
ACKs that request.  Then it never responds to the data phase of the
READ10 command.  This results in not being able to read from the drive.

Some mass storage devices (like the Corsair Survivor USB 3.0 flash
drive) are well behaved.  They ACK the entry into L1 during control
transfers, and when SCSI commands start coming in, they NAK the requests
to go into L1, because they need to be at full power.

Not all USB 3.0 devices advertise USB 2.0 link PM support.  My Point
Grey USB 3.0 webcam advertises itself as a USB 2.1 device, but doesn't
have a USB 2.0 BOS descriptor, so we don't enable USB 2.0 Link PM.  I
suspect that means the device isn't certified.

What do we do about it?
-----------------------

There's really no good way for the kernel to test these devices.
Therefore, the kernel needs to disable USB 2.0 Link PM by default, and
distros will have to enable it by writing 1 to the sysfs file
/sys/bus/usb/devices/../power/usb2_hardware_lpm.  Rip out the xHCI Link
PM test, since it's not sufficient to detect these buggy devices, and
don't automatically enable LPM after the device is addressed.

This patch should be backported to kernels as old as 3.11, that
contain the commit a558ccdc "usb: xhci:
add USB2 Link power management BESL support".  Without this fix, some
USB 3.0 devices will not enumerate or work properly under USB 2.0 ports
on Haswell-ULT systems.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

Use DRIVER_ATTR_RW() to make it easier to audit sysfs file permissions.
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When building the htmldocs (in verbose mode), scripts/kernel-doc reports the
following type of warnings:

Warning(drivers/usb/core/usb.c:76): No description found for return value of
'usb_find_alt_setting'

Fix them by:
- adding some missing descriptions of return values
- using "Return" sections for those descriptions
Signed-off-by: NYacine Belkadi <yacine.belkadi.1@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NMika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: NKevin Hilman <khilman@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: NKevin Hilman <khilman@linaro.org>
Reviewed-by: NUlf Hansson <ulf.hansson@linaro.org>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>

  when suspend, it need check 'udev->actconfig'.
  so when process failure, also need check it.
Signed-off-by: NChen Gang <gang.chen@asianux.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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

This patch adds comments on interface driver suspend callback
to emphasize that the failure return value is ignored by
USB core in system sleep context, so do not try to recover
device for this case and let resume/reset_resume callback
handle the suspend failure if needed.

Also kerneldoc for usb_suspend_both() is updated with the
fact.
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove conditional code based on CONFIG_HOTPLUG being false.  It's
always on now in preparation of it going away as an option.
Signed-off-by: NBill Pemberton <wfp5p@virginia.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Before a driver is probed, we want to disable USB 3.0 Link Power
Management (LPM), in case the driver needs hub-initiated LPM disabled.
After the probe finishes, we want to attempt to re-enable LPM, order to
balance the LPM ref count.

When a probe fails (such as when libusual doesn't want to bind to a USB
3.0 mass storage device), make sure to balance the LPM ref counts by
re-enabling LPM.

This patch should be backported to kernels as old as 3.5, that contain
the commit 8306095f "USB: Disable USB
3.0 LPM in critical sections."
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org

retval is 0, and carefully assigned - and tested as non zero.

This is not useful. While we are at it remove some other bogus initialisation
in the function
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When a whole class of devices (possibly from a specific vendor, or
across multiple vendors) require a quirk, explictly listing all devices
in the class make the quirks table unnecessarily large. Fix this by
allowing matching devices based on interface information.
Signed-off-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Ensure that intfdata always is NULL if no driver is bound:
1) drvdata is for a driver to store a pointer to driver specific data
2) If no driver is bound, there is no driver specific data associated with
   the device
3) Thus logically drvdata should be NULL if no driver is bound.

We already set intfdata to NULL when a driver is unbound, to ensure that
intfdata will be NULL even if the drivers disconnect method does not properly
clear it. This ensures that intfdata will also be NULL after a failed probe,
even if the driver's probe method left a (likely dangling) pointer in there.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Some composite USB devices provide multiple interfaces
with different functions, all using "vendor-specific"
for class/subclass/protocol.  Another OS use interface
numbers to match the driver and interface. It seems
these devices are designed with that in mind - using
static interface numbers for the different functions.

This adds support for matching against the
bInterfaceNumber, allowing such devices to be supported
without having to resort to testing against interface
number whitelists and/or blacklists in the probe.
Signed-off-by: NBjørn Mork <bjorn@mork.no>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There are several places where the USB core needs to disable USB 3.0
Link PM:
 - usb_bind_interface
 - usb_unbind_interface
 - usb_driver_claim_interface
 - usb_port_suspend/usb_port_resume
 - usb_reset_and_verify_device
 - usb_set_interface
 - usb_reset_configuration
 - usb_set_configuration

Use the new LPM disable/enable functions to temporarily disable LPM
around these critical sections.

We need to protect the critical section around binding and unbinding USB
interface drivers.  USB drivers may want to disable hub-initiated USB
3.0 LPM, which will change the value of the U1/U2 timeouts that the xHCI
driver will install.  We need to disable LPM completely until the driver
is bound to the interface, and the driver has a chance to enable
whatever alternate interface setting it needs in its probe routine.
Then re-enable USB3 LPM, and recalculate the U1/U2 timeout values.

We also need to disable LPM in usb_driver_claim_interface,
because drivers like usbfs can bind to an interface through that
function.  Note, there is no way currently for userspace drivers to
disable hub-initiated USB 3.0 LPM.  Revisit this later.

When a driver is unbound, the U1/U2 timeouts may change because we are
unbinding the last driver that needed hub-initiated USB 3.0 LPM to be
disabled.

USB LPM must be disabled when a USB device is going to be suspended.
The USB 3.0 spec does not define a state transition from U1 or U2 into
U3, so we need to bring the device into U0 by disabling LPM before we
can place it into U3.  Therefore, call usb_unlocked_disable_lpm() in
usb_port_suspend(), and call usb_unlocked_enable_lpm() in
usb_port_resume().  If the port suspend fails, make sure to re-enable
LPM by calling usb_unlocked_enable_lpm(), since usb_port_resume() will
not be called on a failed port suspend.

USB 3.0 devices lose their USB 3.0 LPM settings (including whether USB
device-initiated LPM is enabled) across device suspend.  Therefore,
disable LPM before the device will be reset in
usb_reset_and_verify_device(), and re-enable LPM after the reset is
complete and the configuration/alt settings are re-installed.

The calculated U1/U2 timeout values are heavily dependent on what USB
device endpoints are currently enabled.  When any of the enabled
endpoints on the device might change, due to a new configuration, or new
alternate interface setting, we need to first disable USB 3.0 LPM, add
or delete endpoints from the xHCI schedule, install the new interfaces
and alt settings, and then re-enable LPM.  Do this in usb_set_interface,
usb_reset_configuration, and usb_set_configuration.

Basically, there is a call to disable and then enable LPM in all
functions that lock the bandwidth_mutex.  One exception is
usb_disable_device, because the device is disconnecting or otherwise
going away, and we should not care about whether USB 3.0 LPM is enabled.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>

Keep the usb-serial support for dynamic IDs in sync with the usb
support.  This enables readout of dynamic device IDs for
usb-serial drivers.  Common code is exported from the usb core
system and reused by the usb-serial bus driver.
Signed-off-by: NBjørn Mork <bjorn@mork.no>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>