<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include/linux/usb.h, branch v4.4.148</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.4.148</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v4.4.148'/>
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<updated>2017-12-09T17:42:43Z</updated>
<entry>
<title>usb: Add USB 3.1 Precision time measurement capability descriptor support</title>
<updated>2017-12-09T17:42:43Z</updated>
<author>
<name>Mathias Nyman</name>
<email>mathias.nyman@linux.intel.com</email>
</author>
<published>2016-02-12T14:40:14Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=ddaa1ae2eb7ffb4e270fdc9593c3d1138f61fb31'/>
<id>urn:sha1:ddaa1ae2eb7ffb4e270fdc9593c3d1138f61fb31</id>
<content type='text'>
commit faee822c5a7ab99de25cd34fcde3f8d37b6b9923 upstream.

USB 3.1 devices that support precision time measurement have an
additional PTM cabaility descriptor as part of the full BOS descriptor

Look for this descriptor while parsing the BOS descriptor, and store it in
struct usb_hub_bos if it exists.

Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>usb: core: hub: hub_port_init lock controller instead of bus</title>
<updated>2017-03-26T10:13:16Z</updated>
<author>
<name>Chris Bainbridge</name>
<email>chris.bainbridge@gmail.com</email>
</author>
<published>2016-04-25T12:48:38Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=ac1a97d8a562161e42edd23e5d0f1740a3d93c85'/>
<id>urn:sha1:ac1a97d8a562161e42edd23e5d0f1740a3d93c85</id>
<content type='text'>
commit feb26ac31a2a5cb88d86680d9a94916a6343e9e6 upstream.

The XHCI controller presents two USB buses to the system - one for USB2
and one for USB3. The hub init code (hub_port_init) is reentrant but
only locks one bus per thread, leading to a race condition failure when
two threads attempt to simultaneously initialise a USB2 and USB3 device:

[    8.034843] xhci_hcd 0000:00:14.0: Timeout while waiting for setup device command
[   13.183701] usb 3-3: device descriptor read/all, error -110

On a test system this failure occurred on 6% of all boots.

The call traces at the point of failure are:

Call Trace:
 [&lt;ffffffff81b9bab7&gt;] schedule+0x37/0x90
 [&lt;ffffffff817da7cd&gt;] usb_kill_urb+0x8d/0xd0
 [&lt;ffffffff8111e5e0&gt;] ? wake_up_atomic_t+0x30/0x30
 [&lt;ffffffff817dafbe&gt;] usb_start_wait_urb+0xbe/0x150
 [&lt;ffffffff817db10c&gt;] usb_control_msg+0xbc/0xf0
 [&lt;ffffffff817d07de&gt;] hub_port_init+0x51e/0xb70
 [&lt;ffffffff817d4697&gt;] hub_event+0x817/0x1570
 [&lt;ffffffff810f3e6f&gt;] process_one_work+0x1ff/0x620
 [&lt;ffffffff810f3dcf&gt;] ? process_one_work+0x15f/0x620
 [&lt;ffffffff810f4684&gt;] worker_thread+0x64/0x4b0
 [&lt;ffffffff810f4620&gt;] ? rescuer_thread+0x390/0x390
 [&lt;ffffffff810fa7f5&gt;] kthread+0x105/0x120
 [&lt;ffffffff810fa6f0&gt;] ? kthread_create_on_node+0x200/0x200
 [&lt;ffffffff81ba183f&gt;] ret_from_fork+0x3f/0x70
 [&lt;ffffffff810fa6f0&gt;] ? kthread_create_on_node+0x200/0x200

Call Trace:
 [&lt;ffffffff817fd36d&gt;] xhci_setup_device+0x53d/0xa40
 [&lt;ffffffff817fd87e&gt;] xhci_address_device+0xe/0x10
 [&lt;ffffffff817d047f&gt;] hub_port_init+0x1bf/0xb70
 [&lt;ffffffff811247ed&gt;] ? trace_hardirqs_on+0xd/0x10
 [&lt;ffffffff817d4697&gt;] hub_event+0x817/0x1570
 [&lt;ffffffff810f3e6f&gt;] process_one_work+0x1ff/0x620
 [&lt;ffffffff810f3dcf&gt;] ? process_one_work+0x15f/0x620
 [&lt;ffffffff810f4684&gt;] worker_thread+0x64/0x4b0
 [&lt;ffffffff810f4620&gt;] ? rescuer_thread+0x390/0x390
 [&lt;ffffffff810fa7f5&gt;] kthread+0x105/0x120
 [&lt;ffffffff810fa6f0&gt;] ? kthread_create_on_node+0x200/0x200
 [&lt;ffffffff81ba183f&gt;] ret_from_fork+0x3f/0x70
 [&lt;ffffffff810fa6f0&gt;] ? kthread_create_on_node+0x200/0x200

Which results from the two call chains:

hub_port_init
 usb_get_device_descriptor
  usb_get_descriptor
   usb_control_msg
    usb_internal_control_msg
     usb_start_wait_urb
      usb_submit_urb / wait_for_completion_timeout / usb_kill_urb

hub_port_init
 hub_set_address
  xhci_address_device
   xhci_setup_device

Mathias Nyman explains the current behaviour violates the XHCI spec:

 hub_port_reset() will end up moving the corresponding xhci device slot
 to default state.

 As hub_port_reset() is called several times in hub_port_init() it
 sounds reasonable that we could end up with two threads having their
 xhci device slots in default state at the same time, which according to
 xhci 4.5.3 specs still is a big no no:

 "Note: Software shall not transition more than one Device Slot to the
  Default State at a time"

 So both threads fail at their next task after this.
 One fails to read the descriptor, and the other fails addressing the
 device.

Fix this in hub_port_init by locking the USB controller (instead of an
individual bus) to prevent simultaneous initialisation of both buses.

Fixes: 638139eb95d2 ("usb: hub: allow to process more usb hub events in parallel")
Link: https://lkml.org/lkml/2016/2/8/312
Link: https://lkml.org/lkml/2016/2/4/748
Signed-off-by: Chris Bainbridge &lt;chris.bainbridge@gmail.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Acked-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Signed-off-by: Sumit Semwal &lt;sumit.semwal@linaro.org&gt;
 [sumits: minor merge conflict resolution for linux-4.4.y]
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>USB: leave LPM alone if possible when binding/unbinding interface drivers</title>
<updated>2016-06-01T19:15:51Z</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2016-04-29T19:25:17Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=15e67f90026240145fc9ffa84ede62ea35de2971'/>
<id>urn:sha1:15e67f90026240145fc9ffa84ede62ea35de2971</id>
<content type='text'>
commit 6fb650d43da3e7054984dc548eaa88765a94d49f upstream.

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: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Tested-by: Matthew Giassa &lt;matthew@giassa.net&gt;
CC: Mathias Nyman &lt;mathias.nyman@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>usb: core: lpm: fix usb3_hardware_lpm sysfs node</title>
<updated>2016-01-31T19:28:58Z</updated>
<author>
<name>Lu Baolu</name>
<email>baolu.lu@linux.intel.com</email>
</author>
<published>2015-11-14T08:26:32Z</published>
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<id>urn:sha1:877764274280a69a888e1fdb18d411b36dc25c31</id>
<content type='text'>
commit bf5ce5bf3cc7136fd7fe5e8999a580bc93a9c8f6 upstream.

Commit 655fe4effe0f ("usbcore: add sysfs support to xHCI usb3
hardware LPM") introduced usb3_hardware_lpm sysfs node. This
doesn't show the correct status of USB3 U1 and U2 LPM status.

This patch fixes this by replacing usb3_hardware_lpm with two
nodes, usb3_hardware_lpm_u1 (for U1) and usb3_hardware_lpm_u2
(for U2), and recording the U1/U2 LPM status in right places.

This patch should be back-ported to kernels as old as 4.3,
that contains Commit 655fe4effe0f ("usbcore: add sysfs support
to xHCI usb3 hardware LPM").

Signed-off-by: Lu Baolu &lt;baolu.lu@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>usb: store the new usb 3.1 SuperSpeedPlus device capability descriptor</title>
<updated>2015-10-04T09:34:17Z</updated>
<author>
<name>Mathias Nyman</name>
<email>mathias.nyman@linux.intel.com</email>
</author>
<published>2015-10-01T15:40:33Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=3220befddc0da1f4e09fc790a32a9bd8427e8889'/>
<id>urn:sha1:3220befddc0da1f4e09fc790a32a9bd8427e8889</id>
<content type='text'>
If a device supports usb 3.1 SupeerSpeedPlus Gen2 speeds it povides
a SuperSpeedPlus device capability descriptor as a part of its
BOS descriptor. If we find one while parsing the BOS then save it
togeter with the other device capabilities found in the BOS

Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>USB: Added forgotten parameter description for authorized attribute in usb.h</title>
<updated>2015-09-29T02:52:49Z</updated>
<author>
<name>Stefan Koch</name>
<email>stefan.koch10@gmail.com</email>
</author>
<published>2015-09-28T21:59:52Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=07294cc2ea3000da706fd88c8ec7dcfadc715e14'/>
<id>urn:sha1:07294cc2ea3000da706fd88c8ec7dcfadc715e14</id>
<content type='text'>
Signed-off-by: Stefan Koch &lt;stefan.koch10@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>usb: interface authorization: Declare authorized attribute</title>
<updated>2015-09-22T19:08:39Z</updated>
<author>
<name>Stefan Koch</name>
<email>stefan.koch10@gmail.com</email>
</author>
<published>2015-08-25T19:10:05Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=4ad2ddce1a096dea71d42969515d3a64f0d9246f'/>
<id>urn:sha1:4ad2ddce1a096dea71d42969515d3a64f0d9246f</id>
<content type='text'>
The attribute authorized shows the authorization state for an interface.

Signed-off-by: Stefan Koch &lt;stefan.koch10@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>usb: define a generic USB_RESUME_TIMEOUT macro</title>
<updated>2015-04-07T17:58:35Z</updated>
<author>
<name>Felipe Balbi</name>
<email>balbi@ti.com</email>
</author>
<published>2015-02-13T20:34:25Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=62f0342de1f012f3e90607d39e20fce811391169'/>
<id>urn:sha1:62f0342de1f012f3e90607d39e20fce811391169</id>
<content type='text'>
Every USB Host controller should use this new
macro to define for how long resume signalling
should be driven on the bus.

Currently, almost every single USB controller
is using a 20ms timeout for resume signalling.

That's problematic for two reasons:

a) sometimes that 20ms timer expires a little
before 20ms, which makes us fail certification

b) some (many) devices actually need more than
20ms resume signalling.

Sure, in case of (b) we can state that the device
is against the USB spec, but the fact is that
we have no control over which device the certification
lab will use. We also have no control over which host
they will use. Most likely they'll be using a Windows
PC which, again, we have no control over how that
USB stack is written and how long resume signalling
they are using.

At the end of the day, we must make sure Linux passes
electrical compliance when working as Host or as Device
and currently we don't pass compliance as host because
we're driving resume signallig for exactly 20ms and
that confuses certification test setup resulting in
Certification failure.

Cc: &lt;stable@vger.kernel.org&gt; # v3.10+
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Acked-by: Peter Chen &lt;peter.chen@freescale.com&gt;
Signed-off-by: Felipe Balbi &lt;balbi@ti.com&gt;
</content>
</entry>
<entry>
<title>USB: don't cancel queued resets when unbinding drivers</title>
<updated>2015-01-25T12:54:17Z</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2015-01-21T19:02:43Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=524134d422316a59d5464ccbc12036bbe90c5563'/>
<id>urn:sha1:524134d422316a59d5464ccbc12036bbe90c5563</id>
<content type='text'>
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;
Cc: stable &lt;stable@vger.kernel.org&gt; # 3.19
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>usb: Fix typo in `struct usb_host_interface' comment</title>
<updated>2015-01-25T12:48:28Z</updated>
<author>
<name>Chris Rorvick</name>
<email>chris@rorvick.com</email>
</author>
<published>2015-01-15T03:52:28Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=9636c37843c9355c1ab6adcd8491186cbdc3b950'/>
<id>urn:sha1:9636c37843c9355c1ab6adcd8491186cbdc3b950</id>
<content type='text'>
The descriptor member `bNumEndpoints' is plural.

Signed-off-by: Chris Rorvick &lt;chris@rorvick.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
</feed>
