<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/usb/core, branch v3.18.25</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>USB: Add reset-resume quirk for two Plantronics usb headphones.</title>
<updated>2015-10-28T02:14:09+00:00</updated>
<author>
<name>Yao-Wen Mao</name>
<email>yaowen@google.com</email>
</author>
<published>2015-08-31T06:24:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b2aac3f62f292863c348c968524a153eac8dbf5b'/>
<id>b2aac3f62f292863c348c968524a153eac8dbf5b</id>
<content type='text'>
[ Upstream commit 8484bf2981b3d006426ac052a3642c9ce1d8d980 ]

These two headphones need a reset-resume quirk to properly resume to
original volume level.

Signed-off-by: Yao-Wen Mao &lt;yaowen@google.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 8484bf2981b3d006426ac052a3642c9ce1d8d980 ]

These two headphones need a reset-resume quirk to properly resume to
original volume level.

Signed-off-by: Yao-Wen Mao &lt;yaowen@google.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: Add device quirk for Logitech PTZ cameras</title>
<updated>2015-10-28T02:14:08+00:00</updated>
<author>
<name>Vincent Palatin</name>
<email>vpalatin@chromium.org</email>
</author>
<published>2015-10-01T21:10:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=df59346751bb86dbe1778420c27ee8d34986297e'/>
<id>df59346751bb86dbe1778420c27ee8d34986297e</id>
<content type='text'>
[ Upstream commit 72194739f54607bbf8cfded159627a2015381557 ]

Add a device quirk for the Logitech PTZ Pro Camera and its sibling the
ConferenceCam CC3000e Camera.
This fixes the failed camera enumeration on some boot, particularly on
machines with fast CPU.

Tested by connecting a Logitech PTZ Pro Camera to a machine with a
Haswell Core i7-4600U CPU @ 2.10GHz, and doing thousands of reboot cycles
while recording the kernel logs and taking camera picture after each boot.
Before the patch, more than 7% of the boots show some enumeration transfer
failures and in a few of them, the kernel is giving up before actually
enumerating the webcam. After the patch, the enumeration has been correct
on every reboot.

Signed-off-by: Vincent Palatin &lt;vpalatin@chromium.org&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 72194739f54607bbf8cfded159627a2015381557 ]

Add a device quirk for the Logitech PTZ Pro Camera and its sibling the
ConferenceCam CC3000e Camera.
This fixes the failed camera enumeration on some boot, particularly on
machines with fast CPU.

Tested by connecting a Logitech PTZ Pro Camera to a machine with a
Haswell Core i7-4600U CPU @ 2.10GHz, and doing thousands of reboot cycles
while recording the kernel logs and taking camera picture after each boot.
Before the patch, more than 7% of the boots show some enumeration transfer
failures and in a few of them, the kernel is giving up before actually
enumerating the webcam. After the patch, the enumeration has been correct
on every reboot.

Signed-off-by: Vincent Palatin &lt;vpalatin@chromium.org&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: Use the USB_SS_MULT() macro to get the burst multiplier.</title>
<updated>2015-10-28T02:14:06+00:00</updated>
<author>
<name>Mathias Nyman</name>
<email>mathias.nyman@linux.intel.com</email>
</author>
<published>2015-09-21T14:46:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c8759ce78f7dc0b5d7a0ddcd4957cad1bd9ee5f9'/>
<id>c8759ce78f7dc0b5d7a0ddcd4957cad1bd9ee5f9</id>
<content type='text'>
[ Upstream commit ff30cbc8da425754e8ab96904db1d295bd034f27 ]

Bits 1:0 of the bmAttributes are used for the burst multiplier.
The rest of the bits used to be reserved (zero), but USB3.1 takes bit 7
into use.

Use the existing USB_SS_MULT() macro instead to make sure the mult value
and hence max packet calculations are correct for USB3.1 devices.

Note that burst multiplier in bmAttributes is zero based and that
the USB_SS_MULT() macro adds one.

Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit ff30cbc8da425754e8ab96904db1d295bd034f27 ]

Bits 1:0 of the bmAttributes are used for the burst multiplier.
The rest of the bits used to be reserved (zero), but USB3.1 takes bit 7
into use.

Use the existing USB_SS_MULT() macro instead to make sure the mult value
and hence max packet calculations are correct for USB3.1 devices.

Note that burst multiplier in bmAttributes is zero based and that
the USB_SS_MULT() macro adds one.

Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: usbfs: allow URBs to be reaped after disconnection</title>
<updated>2015-08-04T18:38:38+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2015-01-29T16:29:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3e2003cccc9fb5f73a0d251dbb595f4c6e3a08bd'/>
<id>3e2003cccc9fb5f73a0d251dbb595f4c6e3a08bd</id>
<content type='text'>
[ Upstream commit 3f2cee73b650921b2e214bf487b2061a1c266504 ]

The usbfs API has a peculiar hole: Users are not allowed to reap their
URBs after the device has been disconnected.  There doesn't seem to be
any good reason for this; it is an ad-hoc inconsistency.

The patch allows users to issue the USBDEVFS_REAPURB and
USBDEVFS_REAPURBNDELAY ioctls (together with their 32-bit counterparts
on 64-bit systems) even after the device is gone.  If no URBs are
pending for a disconnected device then the ioctls will return -ENODEV
rather than -EAGAIN, because obviously no new URBs will ever be able
to complete.

The patch also adds a new capability flag for
USBDEVFS_GET_CAPABILITIES to indicate that the reap-after-disconnect
feature is supported.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Tested-by: Chris Dickens &lt;christopher.a.dickens@gmail.com&gt;
Acked-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;greg@kroah.com&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 3f2cee73b650921b2e214bf487b2061a1c266504 ]

The usbfs API has a peculiar hole: Users are not allowed to reap their
URBs after the device has been disconnected.  There doesn't seem to be
any good reason for this; it is an ad-hoc inconsistency.

The patch allows users to issue the USBDEVFS_REAPURB and
USBDEVFS_REAPURBNDELAY ioctls (together with their 32-bit counterparts
on 64-bit systems) even after the device is gone.  If no URBs are
pending for a disconnected device then the ioctls will return -ENODEV
rather than -EAGAIN, because obviously no new URBs will ever be able
to complete.

The patch also adds a new capability flag for
USBDEVFS_GET_CAPABILITIES to indicate that the reap-after-disconnect
feature is supported.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Tested-by: Chris Dickens &lt;christopher.a.dickens@gmail.com&gt;
Acked-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;greg@kroah.com&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: devio: fix a condition in async_completed()</title>
<updated>2015-08-04T18:22:06+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@oracle.com</email>
</author>
<published>2015-05-18T12:29:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ece29f5be76e3db17bafbb32250290e9c70d38e7'/>
<id>ece29f5be76e3db17bafbb32250290e9c70d38e7</id>
<content type='text'>
[ Upstream commit 83ed07c5db71bc02bd646d6eb60b48908235cdf9 ]

Static checkers complain that the current condition is never true.  It
seems pretty likely that it's a typo and "URB" was intended instead of
"USB".

Fixes: 3d97ff63f899 ('usbdevfs: Use scatter-gather lists for large bulk transfers')
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 83ed07c5db71bc02bd646d6eb60b48908235cdf9 ]

Static checkers complain that the current condition is never true.  It
seems pretty likely that it's a typo and "URB" was intended instead of
"USB".

Fixes: 3d97ff63f899 ('usbdevfs: Use scatter-gather lists for large bulk transfers')
Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: core: Fix USB 3.0 devices lost in NOTATTACHED state after a hub port reset</title>
<updated>2015-07-04T03:02:22+00:00</updated>
<author>
<name>Robert Schlabbach</name>
<email>Robert.Schlabbach@gmx.net</email>
</author>
<published>2015-05-25T22:27:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d83de3f9798fe8349fbcb61a7a5ea34f2cd80cba'/>
<id>d83de3f9798fe8349fbcb61a7a5ea34f2cd80cba</id>
<content type='text'>
[ Upstream commit fb6d1f7df5d25299fd7b3e84b72b8851d3634764 ]

Fix USB 3.0 devices lost in NOTATTACHED state after a hub port reset.

Dissolve the function hub_port_finish_reset() completely and divide the
actions to be taken into those which need to be done after each reset
attempt and those which need to be done after the full procedure is
complete, and place them in the appropriate places in hub_port_reset().
Also, remove an unneeded forward declaration of hub_port_reset().

Verbose Problem Description:

USB 3.0 devices may be "lost for good" during a hub port reset.
This makes Linux unable to boot from USB 3.0 devices in certain
constellations of host controllers and devices, because the USB device is
lost during initialization, preventing the rootfs from being mounted.

The underlying problem is that in the affected constellations, during the
processing inside hub_port_reset(), the hub link state goes from 0 to
SS.inactive after the initial reset, and back to 0 again only after the
following "warm" reset.

However, hub_port_finish_reset() is called after each reset attempt and
sets the state the connected USB device based on the "preliminary" status
of the hot reset to USB_STATE_NOTATTACHED due to SS.inactive, yet when
the following warm reset is complete and hub_port_finish_reset() is
called again, its call to set the device to USB_STATE_DEFAULT is blocked
by usb_set_device_state() which does not allow taking USB devices out of
USB_STATE_NOTATTACHED state.

Thanks to Alan Stern for guiding me to the proper solution and how to
submit it.

Link: http://lkml.kernel.org/r/trinity-25981484-72a9-4d46-bf17-9c1cf9301a31-1432073240136%20()%203capp-gmx-bs27
Signed-off-by: Robert Schlabbach &lt;robert_s@gmx.net&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit fb6d1f7df5d25299fd7b3e84b72b8851d3634764 ]

Fix USB 3.0 devices lost in NOTATTACHED state after a hub port reset.

Dissolve the function hub_port_finish_reset() completely and divide the
actions to be taken into those which need to be done after each reset
attempt and those which need to be done after the full procedure is
complete, and place them in the appropriate places in hub_port_reset().
Also, remove an unneeded forward declaration of hub_port_reset().

Verbose Problem Description:

USB 3.0 devices may be "lost for good" during a hub port reset.
This makes Linux unable to boot from USB 3.0 devices in certain
constellations of host controllers and devices, because the USB device is
lost during initialization, preventing the rootfs from being mounted.

The underlying problem is that in the affected constellations, during the
processing inside hub_port_reset(), the hub link state goes from 0 to
SS.inactive after the initial reset, and back to 0 again only after the
following "warm" reset.

However, hub_port_finish_reset() is called after each reset attempt and
sets the state the connected USB device based on the "preliminary" status
of the hot reset to USB_STATE_NOTATTACHED due to SS.inactive, yet when
the following warm reset is complete and hub_port_finish_reset() is
called again, its call to set the device to USB_STATE_DEFAULT is blocked
by usb_set_device_state() which does not allow taking USB devices out of
USB_STATE_NOTATTACHED state.

Thanks to Alan Stern for guiding me to the proper solution and how to
submit it.

Link: http://lkml.kernel.org/r/trinity-25981484-72a9-4d46-bf17-9c1cf9301a31-1432073240136%20()%203capp-gmx-bs27
Signed-off-by: Robert Schlabbach &lt;robert_s@gmx.net&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: core: hub: use new USB_RESUME_TIMEOUT</title>
<updated>2015-05-17T23:12:03+00:00</updated>
<author>
<name>Felipe Balbi</name>
<email>balbi@ti.com</email>
</author>
<published>2015-02-13T21:38:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e04bccabf7fb9c1315bf8932558f58288a5e84d9'/>
<id>e04bccabf7fb9c1315bf8932558f58288a5e84d9</id>
<content type='text'>
[ Upstream commit bbc78c07a51f6fd29c227b1220a9016e585358ba ]

Make sure we're using the new macro, so our
resume signaling will always pass certification.

Cc: &lt;stable@vger.kernel.org&gt; # v3.10+
Signed-off-by: Felipe Balbi &lt;balbi@ti.com&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit bbc78c07a51f6fd29c227b1220a9016e585358ba ]

Make sure we're using the new macro, so our
resume signaling will always pass certification.

Cc: &lt;stable@vger.kernel.org&gt; # v3.10+
Signed-off-by: Felipe Balbi &lt;balbi@ti.com&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: usbfs: don't leak kernel data in siginfo</title>
<updated>2015-03-14T19:37:24+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2015-02-13T15:54:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9705b410152451e509ec0049aa1ce6eab79b98e7'/>
<id>9705b410152451e509ec0049aa1ce6eab79b98e7</id>
<content type='text'>
commit f0c2b68198589249afd2b1f2c4e8de8c03e19c16 upstream.

When a signal is delivered, the information in the siginfo structure
is copied to userspace.  Good security practice dicatates that the
unused fields in this structure should be initialized to 0 so that
random kernel stack data isn't exposed to the user.  This patch adds
such an initialization to the two places where usbfs raises signals.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Reported-by: Dave Mielke &lt;dave@mielke.cc&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit f0c2b68198589249afd2b1f2c4e8de8c03e19c16 upstream.

When a signal is delivered, the information in the siginfo structure
is copied to userspace.  Good security practice dicatates that the
unused fields in this structure should be initialized to 0 so that
random kernel stack data isn't exposed to the user.  This patch adds
such an initialization to the two places where usbfs raises signals.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Reported-by: Dave Mielke &lt;dave@mielke.cc&gt;
Signed-off-by: Sasha Levin &lt;sasha.levin@oracle.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: add flag for HCDs that can't receive wakeup requests (isp1760-hcd)</title>
<updated>2015-03-06T22:53:00+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2015-01-29T20:05:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4e5b83d8e80254b1ad0831e4ce1bcb64fbfd830c'/>
<id>4e5b83d8e80254b1ad0831e4ce1bcb64fbfd830c</id>
<content type='text'>
commit 074f9dd55f9cab1b82690ed7e44bcf38b9616ce0 upstream.

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: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Tested-by: Nicolas Pitre &lt;nico@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;greg@kroah.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 074f9dd55f9cab1b82690ed7e44bcf38b9616ce0 upstream.

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: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Tested-by: Nicolas Pitre &lt;nico@linaro.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;greg@kroah.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>USB: don't cancel queued resets when unbinding drivers</title>
<updated>2015-03-06T22:53:00+00:00</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2015-01-21T19:02:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=76730c9fb39242f4f46f36ed07024deeaf29cedd'/>
<id>76730c9fb39242f4f46f36ed07024deeaf29cedd</id>
<content type='text'>
commit 524134d422316a59d5464ccbc12036bbe90c5563 upstream.

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&amp;m=141893165203776&amp;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&amp;m=142175717016628&amp;w=2 for details).
Acquiring the extra references prevents this failure.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Reported-by: Russell King - ARM Linux &lt;linux@arm.linux.org.uk&gt;
Reported-by: Olivier Sobrie &lt;olivier@sobrie.be&gt;
Tested-by: Olivier Sobrie &lt;olivier@sobrie.be&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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<pre>
commit 524134d422316a59d5464ccbc12036bbe90c5563 upstream.

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&amp;m=141893165203776&amp;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&amp;m=142175717016628&amp;w=2 for details).
Acquiring the extra references prevents this failure.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Reported-by: Russell King - ARM Linux &lt;linux@arm.linux.org.uk&gt;
Reported-by: Olivier Sobrie &lt;olivier@sobrie.be&gt;
Tested-by: Olivier Sobrie &lt;olivier@sobrie.be&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
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