<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/usb/host, branch v6.6.86</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>usb: xhci: Enable the TRB overfetch quirk on VIA VL805</title>
<updated>2025-03-13T11:58:35+00:00</updated>
<author>
<name>Michal Pecio</name>
<email>michal.pecio@gmail.com</email>
</author>
<published>2025-02-25T09:59:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c401b1b4b835d66792e884b76264d742a20d931d'/>
<id>c401b1b4b835d66792e884b76264d742a20d931d</id>
<content type='text'>
commit c133ec0e5717868c9967fa3df92a55e537b1aead upstream.

Raspberry Pi is a major user of those chips and they discovered a bug -
when the end of a transfer ring segment is reached, up to four TRBs can
be prefetched from the next page even if the segment ends with link TRB
and on page boundary (the chip claims to support standard 4KB pages).

It also appears that if the prefetched TRBs belong to a different ring
whose doorbell is later rung, they may be used without refreshing from
system RAM and the endpoint will stay idle if their cycle bit is stale.

Other users complain about IOMMU faults on x86 systems, unsurprisingly.

Deal with it by using existing quirk which allocates a dummy page after
each transfer ring segment. This was seen to resolve both problems. RPi
came up with a more efficient solution, shortening each segment by four
TRBs, but it complicated the driver and they ditched it for this quirk.

Also rename the quirk and add VL805 device ID macro.

Signed-off-by: Michal Pecio &lt;michal.pecio@gmail.com&gt;
Link: https://github.com/raspberrypi/linux/issues/4685
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=215906
CC: stable@vger.kernel.org
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20250225095927.2512358-2-mathias.nyman@linux.intel.com
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 c133ec0e5717868c9967fa3df92a55e537b1aead upstream.

Raspberry Pi is a major user of those chips and they discovered a bug -
when the end of a transfer ring segment is reached, up to four TRBs can
be prefetched from the next page even if the segment ends with link TRB
and on page boundary (the chip claims to support standard 4KB pages).

It also appears that if the prefetched TRBs belong to a different ring
whose doorbell is later rung, they may be used without refreshing from
system RAM and the endpoint will stay idle if their cycle bit is stale.

Other users complain about IOMMU faults on x86 systems, unsurprisingly.

Deal with it by using existing quirk which allocates a dummy page after
each transfer ring segment. This was seen to resolve both problems. RPi
came up with a more efficient solution, shortening each segment by four
TRBs, but it complicated the driver and they ditched it for this quirk.

Also rename the quirk and add VL805 device ID macro.

Signed-off-by: Michal Pecio &lt;michal.pecio@gmail.com&gt;
Link: https://github.com/raspberrypi/linux/issues/4685
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=215906
CC: stable@vger.kernel.org
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20250225095927.2512358-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xhci: pci: Fix indentation in the PCI device ID definitions</title>
<updated>2025-03-13T11:58:35+00:00</updated>
<author>
<name>Andy Shevchenko</name>
<email>andriy.shevchenko@linux.intel.com</email>
</author>
<published>2024-11-06T10:14:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=af091756c4c7e7b73b619ae68eeaef701cd74022'/>
<id>af091756c4c7e7b73b619ae68eeaef701cd74022</id>
<content type='text'>
commit 0309ed83791c079f239c13e0c605210425cd1a61 upstream.

Some of the definitions are missing the one TAB, add it to them.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20241106101459.775897-23-mathias.nyman@linux.intel.com
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 0309ed83791c079f239c13e0c605210425cd1a61 upstream.

Some of the definitions are missing the one TAB, add it to them.

Signed-off-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20241106101459.775897-23-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: pci-quirks: Fix HCCPARAMS register error for LS7A EHCI</title>
<updated>2025-02-21T12:57:14+00:00</updated>
<author>
<name>Huacai Chen</name>
<email>chenhuacai@loongson.cn</email>
</author>
<published>2025-02-02T12:49:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=add6d8a137cbe80e2ba07116acaac4496b0d043e'/>
<id>add6d8a137cbe80e2ba07116acaac4496b0d043e</id>
<content type='text'>
commit e71f7f42e3c874ac3314b8f250e8416a706165af upstream.

LS7A EHCI controller doesn't have extended capabilities, so the EECP
(EHCI Extended Capabilities Pointer) field of HCCPARAMS register should
be 0x0, but it reads as 0xa0 now. This is a hardware flaw and will be
fixed in future, now just clear the EECP field to avoid error messages
on boot:

......
[    0.581675] pci 0000:00:04.1: EHCI: unrecognized capability ff
[    0.581699] pci 0000:00:04.1: EHCI: unrecognized capability ff
[    0.581716] pci 0000:00:04.1: EHCI: unrecognized capability ff
[    0.581851] pci 0000:00:04.1: EHCI: unrecognized capability ff
......
[    0.581916] pci 0000:00:05.1: EHCI: unrecognized capability ff
[    0.581951] pci 0000:00:05.1: EHCI: unrecognized capability ff
[    0.582704] pci 0000:00:05.1: EHCI: unrecognized capability ff
[    0.582799] pci 0000:00:05.1: EHCI: unrecognized capability ff
......

Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Baoqi Zhang &lt;zhangbaoqi@loongson.cn&gt;
Signed-off-by: Huacai Chen &lt;chenhuacai@loongson.cn&gt;
Link: https://lore.kernel.org/r/20250202124935.480500-1-chenhuacai@loongson.cn
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 e71f7f42e3c874ac3314b8f250e8416a706165af upstream.

LS7A EHCI controller doesn't have extended capabilities, so the EECP
(EHCI Extended Capabilities Pointer) field of HCCPARAMS register should
be 0x0, but it reads as 0xa0 now. This is a hardware flaw and will be
fixed in future, now just clear the EECP field to avoid error messages
on boot:

......
[    0.581675] pci 0000:00:04.1: EHCI: unrecognized capability ff
[    0.581699] pci 0000:00:04.1: EHCI: unrecognized capability ff
[    0.581716] pci 0000:00:04.1: EHCI: unrecognized capability ff
[    0.581851] pci 0000:00:04.1: EHCI: unrecognized capability ff
......
[    0.581916] pci 0000:00:05.1: EHCI: unrecognized capability ff
[    0.581951] pci 0000:00:05.1: EHCI: unrecognized capability ff
[    0.582704] pci 0000:00:05.1: EHCI: unrecognized capability ff
[    0.582799] pci 0000:00:05.1: EHCI: unrecognized capability ff
......

Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Baoqi Zhang &lt;zhangbaoqi@loongson.cn&gt;
Signed-off-by: Huacai Chen &lt;chenhuacai@loongson.cn&gt;
Link: https://lore.kernel.org/r/20250202124935.480500-1-chenhuacai@loongson.cn
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: xhci: Fix NULL pointer dereference on certain command aborts</title>
<updated>2025-02-08T08:52:36+00:00</updated>
<author>
<name>Michal Pecio</name>
<email>michal.pecio@gmail.com</email>
</author>
<published>2024-12-27T12:01:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b649f0d5bc256f691c7d234c3986685d54053de1'/>
<id>b649f0d5bc256f691c7d234c3986685d54053de1</id>
<content type='text'>
commit 1e0a19912adb68a4b2b74fd77001c96cd83eb073 upstream.

If a command is queued to the final usable TRB of a ring segment, the
enqueue pointer is advanced to the subsequent link TRB and no further.
If the command is later aborted, when the abort completion is handled
the dequeue pointer is advanced to the first TRB of the next segment.

If no further commands are queued, xhci_handle_stopped_cmd_ring() sees
the ring pointers unequal and assumes that there is a pending command,
so it calls xhci_mod_cmd_timer() which crashes if cur_cmd was NULL.

Don't attempt timer setup if cur_cmd is NULL. The subsequent doorbell
ring likely is unnecessary too, but it's harmless. Leave it alone.

This is probably Bug 219532, but no confirmation has been received.

The issue has been independently reproduced and confirmed fixed using
a USB MCU programmed to NAK the Status stage of SET_ADDRESS forever.
Everything continued working normally after several prevented crashes.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=219532
Fixes: c311e391a7ef ("xhci: rework command timeout and cancellation,")
CC: stable@vger.kernel.org
Signed-off-by: Michal Pecio &lt;michal.pecio@gmail.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20241227120142.1035206-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&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 1e0a19912adb68a4b2b74fd77001c96cd83eb073 upstream.

If a command is queued to the final usable TRB of a ring segment, the
enqueue pointer is advanced to the subsequent link TRB and no further.
If the command is later aborted, when the abort completion is handled
the dequeue pointer is advanced to the first TRB of the next segment.

If no further commands are queued, xhci_handle_stopped_cmd_ring() sees
the ring pointers unequal and assumes that there is a pending command,
so it calls xhci_mod_cmd_timer() which crashes if cur_cmd was NULL.

Don't attempt timer setup if cur_cmd is NULL. The subsequent doorbell
ring likely is unnecessary too, but it's harmless. Leave it alone.

This is probably Bug 219532, but no confirmation has been received.

The issue has been independently reproduced and confirmed fixed using
a USB MCU programmed to NAK the Status stage of SET_ADDRESS forever.
Everything continued working normally after several prevented crashes.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=219532
Fixes: c311e391a7ef ("xhci: rework command timeout and cancellation,")
CC: stable@vger.kernel.org
Signed-off-by: Michal Pecio &lt;michal.pecio@gmail.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20241227120142.1035206-4-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: xhci: Avoid queuing redundant Stop Endpoint commands</title>
<updated>2025-01-09T12:31:53+00:00</updated>
<author>
<name>Michal Pecio</name>
<email>michal.pecio@gmail.com</email>
</author>
<published>2024-11-06T10:14:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8b2e38f2a9b71af39f5697c30113136d4a5cae1a'/>
<id>8b2e38f2a9b71af39f5697c30113136d4a5cae1a</id>
<content type='text'>
[ Upstream commit 474538b8dd1cd9c666e56cfe8ef60fbb0fb513f4 ]

Stop Endpoint command on an already stopped endpoint fails and may be
misinterpreted as a known hardware bug by the completion handler. This
results in an unnecessary delay with repeated retries of the command.

Avoid queuing this command when endpoint state flags indicate that it's
stopped or halted and the command will fail. If commands are pending on
the endpoint, their completion handlers will process cancelled TDs so
it's done. In case of waiting for external operations like clearing TT
buffer, the endpoint is stopped and cancelled TDs can be processed now.

This eliminates practically all unnecessary retries because an endpoint
with pending URBs is maintained in Running state by the driver, unless
aforementioned commands or other operations are pending on it. This is
guaranteed by xhci_ring_ep_doorbell() and by the fact that it is called
every time any of those operations completes.

The only known exceptions are hardware bugs (the endpoint never starts
at all) and Stream Protocol errors not associated with any TRB, which
cause an endpoint reset not followed by restart. Sounds like a bug.

Generally, these retries are only expected to happen when the endpoint
fails to start for unknown/no reason, which is a worse problem itself,
and fixing the bug eliminates the retries too.

All cases were tested and found to work as expected. SET_DEQ_PENDING
was produced by patching uvcvideo to unlink URBs in 100us intervals,
which then runs into this case very often. EP_HALTED was produced by
restarting 'cat /dev/ttyUSB0' on a serial dongle with broken cable.
EP_CLEARING_TT by the same, with the dongle on an external hub.

Fixes: fd9d55d190c0 ("xhci: retry Stop Endpoint on buggy NEC controllers")
CC: stable@vger.kernel.org
Signed-off-by: Michal Pecio &lt;michal.pecio@gmail.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20241106101459.775897-34-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 474538b8dd1cd9c666e56cfe8ef60fbb0fb513f4 ]

Stop Endpoint command on an already stopped endpoint fails and may be
misinterpreted as a known hardware bug by the completion handler. This
results in an unnecessary delay with repeated retries of the command.

Avoid queuing this command when endpoint state flags indicate that it's
stopped or halted and the command will fail. If commands are pending on
the endpoint, their completion handlers will process cancelled TDs so
it's done. In case of waiting for external operations like clearing TT
buffer, the endpoint is stopped and cancelled TDs can be processed now.

This eliminates practically all unnecessary retries because an endpoint
with pending URBs is maintained in Running state by the driver, unless
aforementioned commands or other operations are pending on it. This is
guaranteed by xhci_ring_ep_doorbell() and by the fact that it is called
every time any of those operations completes.

The only known exceptions are hardware bugs (the endpoint never starts
at all) and Stream Protocol errors not associated with any TRB, which
cause an endpoint reset not followed by restart. Sounds like a bug.

Generally, these retries are only expected to happen when the endpoint
fails to start for unknown/no reason, which is a worse problem itself,
and fixing the bug eliminates the retries too.

All cases were tested and found to work as expected. SET_DEQ_PENDING
was produced by patching uvcvideo to unlink URBs in 100us intervals,
which then runs into this case very often. EP_HALTED was produced by
restarting 'cat /dev/ttyUSB0' on a serial dongle with broken cable.
EP_CLEARING_TT by the same, with the dongle on an external hub.

Fixes: fd9d55d190c0 ("xhci: retry Stop Endpoint on buggy NEC controllers")
CC: stable@vger.kernel.org
Signed-off-by: Michal Pecio &lt;michal.pecio@gmail.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20241106101459.775897-34-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xhci: Turn NEC specific quirk for handling Stop Endpoint errors generic</title>
<updated>2025-01-09T12:31:48+00:00</updated>
<author>
<name>Mathias Nyman</name>
<email>mathias.nyman@linux.intel.com</email>
</author>
<published>2024-12-17T10:21:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6cd8e621a689b0b3f25b384702c2574f06ad1edb'/>
<id>6cd8e621a689b0b3f25b384702c2574f06ad1edb</id>
<content type='text'>
[ Upstream commit e21ebe51af688eb98fd6269240212a3c7300deea ]

xHC hosts from several vendors have the same issue where endpoints start
so slowly that a later queued 'Stop Endpoint' command may complete before
endpoint is up and running.

The 'Stop Endpoint' command fails with context state error as the endpoint
still appears as  stopped.

See commit 42b758137601 ("usb: xhci: Limit Stop Endpoint retries") for
details

CC: stable@vger.kernel.org
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20241217102122.2316814-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit e21ebe51af688eb98fd6269240212a3c7300deea ]

xHC hosts from several vendors have the same issue where endpoints start
so slowly that a later queued 'Stop Endpoint' command may complete before
endpoint is up and running.

The 'Stop Endpoint' command fails with context state error as the endpoint
still appears as  stopped.

See commit 42b758137601 ("usb: xhci: Limit Stop Endpoint retries") for
details

CC: stable@vger.kernel.org
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20241217102122.2316814-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: xhci: Limit Stop Endpoint retries</title>
<updated>2025-01-09T12:31:48+00:00</updated>
<author>
<name>Michal Pecio</name>
<email>michal.pecio@gmail.com</email>
</author>
<published>2024-11-06T10:14:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f1ece345ad2c5820d10eb29f07bebc378295d5be'/>
<id>f1ece345ad2c5820d10eb29f07bebc378295d5be</id>
<content type='text'>
[ Upstream commit 42b7581376015c1bbcbe5831f043cd0ac119d028 ]

Some host controllers fail to atomically transition an endpoint to the
Running state on a doorbell ring and enter a hidden "Restarting" state,
which looks very much like Stopped, with the important difference that
it will spontaneously transition to Running anytime soon.

A Stop Endpoint command queued in the Restarting state typically fails
with Context State Error and the completion handler sees the Endpoint
Context State as either still Stopped or already Running. Even a case
of Halted was observed, when an error occurred right after the restart.

The Halted state is already recovered from by resetting the endpoint.
The Running state is handled by retrying Stop Endpoint.

The Stopped state was recognized as a problem on NEC controllers and
worked around also by retrying, because the endpoint soon restarts and
then stops for good. But there is a risk: the command may fail if the
endpoint is "stopped for good" already, and retries will fail forever.

The possibility of this was not realized at the time, but a number of
cases were discovered later and reproduced. Some proved difficult to
deal with, and it is outright impossible to predict if an endpoint may
fail to ever start at all due to a hardware bug. One such bug (albeit
on ASM3142, not on NEC) was found to be reliably triggered simply by
toggling an AX88179 NIC up/down in a tight loop for a few seconds.

An endless retries storm is quite nasty. Besides putting needless load
on the xHC and CPU, it causes URBs never to be given back, paralyzing
the device and connection/disconnection logic for the whole bus if the
device is unplugged. User processes waiting for URBs become unkillable,
drivers and kworker threads lock up and xhci_hcd cannot be reloaded.

For peace of mind, impose a timeout on Stop Endpoint retries in this
case. If they don't succeed in 100ms, consider the endpoint stopped
permanently for some reason and just give back the unlinked URBs. This
failure case is rare already and work is under way to make it rarer.

Start this work today by also handling one simple case of race with
Reset Endpoint, because it costs just two lines to implement.

Fixes: fd9d55d190c0 ("xhci: retry Stop Endpoint on buggy NEC controllers")
CC: stable@vger.kernel.org
Signed-off-by: Michal Pecio &lt;michal.pecio@gmail.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20241106101459.775897-32-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Stable-dep-of: e21ebe51af68 ("xhci: Turn NEC specific quirk for handling Stop Endpoint errors generic")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 42b7581376015c1bbcbe5831f043cd0ac119d028 ]

Some host controllers fail to atomically transition an endpoint to the
Running state on a doorbell ring and enter a hidden "Restarting" state,
which looks very much like Stopped, with the important difference that
it will spontaneously transition to Running anytime soon.

A Stop Endpoint command queued in the Restarting state typically fails
with Context State Error and the completion handler sees the Endpoint
Context State as either still Stopped or already Running. Even a case
of Halted was observed, when an error occurred right after the restart.

The Halted state is already recovered from by resetting the endpoint.
The Running state is handled by retrying Stop Endpoint.

The Stopped state was recognized as a problem on NEC controllers and
worked around also by retrying, because the endpoint soon restarts and
then stops for good. But there is a risk: the command may fail if the
endpoint is "stopped for good" already, and retries will fail forever.

The possibility of this was not realized at the time, but a number of
cases were discovered later and reproduced. Some proved difficult to
deal with, and it is outright impossible to predict if an endpoint may
fail to ever start at all due to a hardware bug. One such bug (albeit
on ASM3142, not on NEC) was found to be reliably triggered simply by
toggling an AX88179 NIC up/down in a tight loop for a few seconds.

An endless retries storm is quite nasty. Besides putting needless load
on the xHC and CPU, it causes URBs never to be given back, paralyzing
the device and connection/disconnection logic for the whole bus if the
device is unplugged. User processes waiting for URBs become unkillable,
drivers and kworker threads lock up and xhci_hcd cannot be reloaded.

For peace of mind, impose a timeout on Stop Endpoint retries in this
case. If they don't succeed in 100ms, consider the endpoint stopped
permanently for some reason and just give back the unlinked URBs. This
failure case is rare already and work is under way to make it rarer.

Start this work today by also handling one simple case of race with
Reset Endpoint, because it costs just two lines to implement.

Fixes: fd9d55d190c0 ("xhci: retry Stop Endpoint on buggy NEC controllers")
CC: stable@vger.kernel.org
Signed-off-by: Michal Pecio &lt;michal.pecio@gmail.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20241106101459.775897-32-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Stable-dep-of: e21ebe51af68 ("xhci: Turn NEC specific quirk for handling Stop Endpoint errors generic")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xhci: retry Stop Endpoint on buggy NEC controllers</title>
<updated>2025-01-09T12:31:48+00:00</updated>
<author>
<name>Michal Pecio</name>
<email>michal.pecio@gmail.com</email>
</author>
<published>2024-02-29T14:14:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=61329b25dc1dc93a35167189e0295166003edb29'/>
<id>61329b25dc1dc93a35167189e0295166003edb29</id>
<content type='text'>
[ Upstream commit fd9d55d190c0e5fefd3a9165ea361809427885a1 ]

Two NEC uPD720200 adapters have been observed to randomly misbehave:
a Stop Endpoint command fails with Context Error, the Output Context
indicates Stopped state, and the endpoint keeps running. Very often,
Set TR Dequeue Pointer is seen to fail next with Context Error too,
in addition to problems from unexpectedly completed cancelled work.

The pathology is common on fast running isoc endpoints like uvcvideo,
but has also been reproduced on a full-speed bulk endpoint of pl2303.
It seems all EPs are affected, with risk proportional to their load.

Reproduction involves receiving any kind of stream and closing it to
make the device driver cancel URBs already queued in advance.

Deal with it by retrying the command like in the Running state.

Signed-off-by: Michal Pecio &lt;michal.pecio@gmail.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20240229141438.619372-8-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Stable-dep-of: e21ebe51af68 ("xhci: Turn NEC specific quirk for handling Stop Endpoint errors generic")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit fd9d55d190c0e5fefd3a9165ea361809427885a1 ]

Two NEC uPD720200 adapters have been observed to randomly misbehave:
a Stop Endpoint command fails with Context Error, the Output Context
indicates Stopped state, and the endpoint keeps running. Very often,
Set TR Dequeue Pointer is seen to fail next with Context Error too,
in addition to problems from unexpectedly completed cancelled work.

The pathology is common on fast running isoc endpoints like uvcvideo,
but has also been reproduced on a full-speed bulk endpoint of pl2303.
It seems all EPs are affected, with risk proportional to their load.

Reproduction involves receiving any kind of stream and closing it to
make the device driver cancel URBs already queued in advance.

Deal with it by retrying the command like in the Running state.

Signed-off-by: Michal Pecio &lt;michal.pecio@gmail.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20240229141438.619372-8-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Stable-dep-of: e21ebe51af68 ("xhci: Turn NEC specific quirk for handling Stop Endpoint errors generic")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: ehci-hcd: fix call balance of clocks handling routines</title>
<updated>2024-12-19T17:11:23+00:00</updated>
<author>
<name>Vitalii Mordan</name>
<email>mordan@ispras.ru</email>
</author>
<published>2024-11-21T11:47:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e22e4df241f76b066dff4ba4eb9f91fd502c3089'/>
<id>e22e4df241f76b066dff4ba4eb9f91fd502c3089</id>
<content type='text'>
commit 97264eaaba0122a5b7e8ddd7bf4ff3ac57c2b170 upstream.

If the clocks priv-&gt;iclk and priv-&gt;fclk were not enabled in ehci_hcd_sh_probe,
they should not be disabled in any path.

Conversely, if they was enabled in ehci_hcd_sh_probe, they must be disabled
in all error paths to ensure proper cleanup.

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

Fixes: 63c845522263 ("usb: ehci-hcd: Add support for SuperH EHCI.")
Cc: stable@vger.kernel.org # ff30bd6a6618: sh: clk: Fix clk_enable() to return 0 on NULL clk
Signed-off-by: Vitalii Mordan &lt;mordan@ispras.ru&gt;
Reviewed-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Link: https://lore.kernel.org/r/20241121114700.2100520-1-mordan@ispras.ru
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 97264eaaba0122a5b7e8ddd7bf4ff3ac57c2b170 upstream.

If the clocks priv-&gt;iclk and priv-&gt;fclk were not enabled in ehci_hcd_sh_probe,
they should not be disabled in any path.

Conversely, if they was enabled in ehci_hcd_sh_probe, they must be disabled
in all error paths to ensure proper cleanup.

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

Fixes: 63c845522263 ("usb: ehci-hcd: Add support for SuperH EHCI.")
Cc: stable@vger.kernel.org # ff30bd6a6618: sh: clk: Fix clk_enable() to return 0 on NULL clk
Signed-off-by: Vitalii Mordan &lt;mordan@ispras.ru&gt;
Reviewed-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Link: https://lore.kernel.org/r/20241121114700.2100520-1-mordan@ispras.ru
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: host: max3421-hcd: Correctly abort a USB request.</title>
<updated>2024-12-19T17:11:22+00:00</updated>
<author>
<name>Mark Tomlinson</name>
<email>mark.tomlinson@alliedtelesis.co.nz</email>
</author>
<published>2024-11-24T22:14:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a867bf10364a597df23ba0b71872211cfb6208ef'/>
<id>a867bf10364a597df23ba0b71872211cfb6208ef</id>
<content type='text'>
commit 0d2ada05227881f3d0722ca2364e3f7a860a301f upstream.

If the current USB request was aborted, the spi thread would not respond
to any further requests. This is because the "curr_urb" pointer would
not become NULL, so no further requests would be taken off the queue.
The solution here is to set the "urb_done" flag, as this will cause the
correct handling of the URB. Also clear interrupts that should only be
expected if an URB is in progress.

Fixes: 2d53139f3162 ("Add support for using a MAX3421E chip as a host driver.")
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Mark Tomlinson &lt;mark.tomlinson@alliedtelesis.co.nz&gt;
Link: https://lore.kernel.org/r/20241124221430.1106080-1-mark.tomlinson@alliedtelesis.co.nz
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 0d2ada05227881f3d0722ca2364e3f7a860a301f upstream.

If the current USB request was aborted, the spi thread would not respond
to any further requests. This is because the "curr_urb" pointer would
not become NULL, so no further requests would be taken off the queue.
The solution here is to set the "urb_done" flag, as this will cause the
correct handling of the URB. Also clear interrupts that should only be
expected if an URB is in progress.

Fixes: 2d53139f3162 ("Add support for using a MAX3421E chip as a host driver.")
Cc: stable &lt;stable@kernel.org&gt;
Signed-off-by: Mark Tomlinson &lt;mark.tomlinson@alliedtelesis.co.nz&gt;
Link: https://lore.kernel.org/r/20241124221430.1106080-1-mark.tomlinson@alliedtelesis.co.nz
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
