<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/usb/host, branch v4.4.283</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>USB:ehci:fix Kunpeng920 ehci hardware problem</title>
<updated>2021-08-15T10:59:56+00:00</updated>
<author>
<name>Longfang Liu</name>
<email>liulongfang@huawei.com</email>
</author>
<published>2021-04-09T08:48:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c643a57ca5bcb01cd97193555f67a2b506739e59'/>
<id>c643a57ca5bcb01cd97193555f67a2b506739e59</id>
<content type='text'>
commit 26b75952ca0b8b4b3050adb9582c8e2f44d49687 upstream.

Kunpeng920's EHCI controller does not have SBRN register.
Reading the SBRN register when the controller driver is
initialized will get 0.

When rebooting the EHCI driver, ehci_shutdown() will be called.
if the sbrn flag is 0, ehci_shutdown() will return directly.
The sbrn flag being 0 will cause the EHCI interrupt signal to
not be turned off after reboot. this interrupt that is not closed
will cause an exception to the device sharing the interrupt.

Therefore, the EHCI controller of Kunpeng920 needs to skip
the read operation of the SBRN register.

Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Longfang Liu &lt;liulongfang@huawei.com&gt;
Link: https://lore.kernel.org/r/1617958081-17999-1-git-send-email-liulongfang@huawei.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 26b75952ca0b8b4b3050adb9582c8e2f44d49687 upstream.

Kunpeng920's EHCI controller does not have SBRN register.
Reading the SBRN register when the controller driver is
initialized will get 0.

When rebooting the EHCI driver, ehci_shutdown() will be called.
if the sbrn flag is 0, ehci_shutdown() will return directly.
The sbrn flag being 0 will cause the EHCI interrupt signal to
not be turned off after reboot. this interrupt that is not closed
will cause an exception to the device sharing the interrupt.

Therefore, the EHCI controller of Kunpeng920 needs to skip
the read operation of the SBRN register.

Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Longfang Liu &lt;liulongfang@huawei.com&gt;
Link: https://lore.kernel.org/r/1617958081-17999-1-git-send-email-liulongfang@huawei.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: max-3421: Prevent corruption of freed memory</title>
<updated>2021-07-28T07:12:36+00:00</updated>
<author>
<name>Mark Tomlinson</name>
<email>mark.tomlinson@alliedtelesis.co.nz</email>
</author>
<published>2021-06-25T03:14:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fc2a7c2280fa2be8ff9b5af702368fcd49a0acdb'/>
<id>fc2a7c2280fa2be8ff9b5af702368fcd49a0acdb</id>
<content type='text'>
commit b5fdf5c6e6bee35837e160c00ac89327bdad031b upstream.

The MAX-3421 USB driver remembers the state of the USB toggles for a
device/endpoint. To save SPI writes, this was only done when a new
device/endpoint was being used. Unfortunately, if the old device was
removed, this would cause writes to freed memory.

To fix this, a simpler scheme is used. The toggles are read from
hardware when a URB is completed, and the toggles are always written to
hardware when any URB transaction is started. This will cause a few more
SPI transactions, but no causes kernel panics.

Fixes: 2d53139f3162 ("Add support for using a MAX3421E chip as a host driver.")
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Mark Tomlinson &lt;mark.tomlinson@alliedtelesis.co.nz&gt;
Link: https://lore.kernel.org/r/20210625031456.8632-1-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 b5fdf5c6e6bee35837e160c00ac89327bdad031b upstream.

The MAX-3421 USB driver remembers the state of the USB toggles for a
device/endpoint. To save SPI writes, this was only done when a new
device/endpoint was being used. Unfortunately, if the old device was
removed, this would cause writes to freed memory.

To fix this, a simpler scheme is used. The toggles are read from
hardware when a URB is completed, and the toggles are always written to
hardware when any URB transaction is started. This will cause a few more
SPI transactions, but no causes kernel panics.

Fixes: 2d53139f3162 ("Add support for using a MAX3421E chip as a host driver.")
Cc: stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Mark Tomlinson &lt;mark.tomlinson@alliedtelesis.co.nz&gt;
Link: https://lore.kernel.org/r/20210625031456.8632-1-mark.tomlinson@alliedtelesis.co.nz
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xhci: Fix lost USB 2 remote wake</title>
<updated>2021-07-28T07:12:36+00:00</updated>
<author>
<name>Mathias Nyman</name>
<email>mathias.nyman@linux.intel.com</email>
</author>
<published>2021-07-15T15:06:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=881d67d762db38e95399dfdab321778378f77090'/>
<id>881d67d762db38e95399dfdab321778378f77090</id>
<content type='text'>
commit 72f68bf5c756f5ce1139b31daae2684501383ad5 upstream.

There's a small window where a USB 2 remote wake may be left unhandled
due to a race between hub thread and xhci port event interrupt handler.

When the resume event is detected in the xhci interrupt handler it kicks
the hub timer, which should move the port from resume to U0 once resume
has been signalled for long enough.

To keep the hub "thread" running we set a bus_state-&gt;resuming_ports flag.
This flag makes sure hub timer function kicks itself.

checking this flag was not properly protected by the spinlock. Flag was
copied to a local variable before lock was taken. The local variable was
then checked later with spinlock held.

If interrupt is handled right after copying the flag to the local variable
we end up stopping the hub thread before it can handle the USB 2 resume.

CPU0					CPU1
(hub thread)				(xhci event handler)

xhci_hub_status_data()
status = bus_state-&gt;resuming_ports;
					&lt;Interrupt&gt;
					handle_port_status()
					spin_lock()
					bus_state-&gt;resuming_ports = 1
					set_flag(HCD_FLAG_POLL_RH)
					spin_unlock()
spin_lock()
if (!status)
  clear_flag(HCD_FLAG_POLL_RH)
spin_unlock()

Fix this by taking the lock a bit earlier so that it covers
the resuming_ports flag copy in the hub thread

Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20210715150651.1996099-2-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 72f68bf5c756f5ce1139b31daae2684501383ad5 upstream.

There's a small window where a USB 2 remote wake may be left unhandled
due to a race between hub thread and xhci port event interrupt handler.

When the resume event is detected in the xhci interrupt handler it kicks
the hub timer, which should move the port from resume to U0 once resume
has been signalled for long enough.

To keep the hub "thread" running we set a bus_state-&gt;resuming_ports flag.
This flag makes sure hub timer function kicks itself.

checking this flag was not properly protected by the spinlock. Flag was
copied to a local variable before lock was taken. The local variable was
then checked later with spinlock held.

If interrupt is handled right after copying the flag to the local variable
we end up stopping the hub thread before it can handle the USB 2 resume.

CPU0					CPU1
(hub thread)				(xhci event handler)

xhci_hub_status_data()
status = bus_state-&gt;resuming_ports;
					&lt;Interrupt&gt;
					handle_port_status()
					spin_lock()
					bus_state-&gt;resuming_ports = 1
					set_flag(HCD_FLAG_POLL_RH)
					spin_unlock()
spin_lock()
if (!status)
  clear_flag(HCD_FLAG_POLL_RH)
spin_unlock()

Fix this by taking the lock a bit earlier so that it covers
the resuming_ports flag copy in the hub thread

Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20210715150651.1996099-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xhci: Do not use GFP_KERNEL in (potentially) atomic context</title>
<updated>2021-05-22T08:38:30+00:00</updated>
<author>
<name>Christophe JAILLET</name>
<email>christophe.jaillet@wanadoo.fr</email>
</author>
<published>2021-05-12T08:08:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d744ccbfb5aeb451617cc6b73a3fa0a102db0c2c'/>
<id>d744ccbfb5aeb451617cc6b73a3fa0a102db0c2c</id>
<content type='text'>
commit dda32c00c9a0fa103b5d54ef72c477b7aa993679 upstream.

'xhci_urb_enqueue()' is passed a 'mem_flags' argument, because "URBs may be
submitted in interrupt context" (see comment related to 'usb_submit_urb()'
in 'drivers/usb/core/urb.c')

So this flag should be used in all the calling chain.
Up to now, 'xhci_check_maxpacket()' which is only called from
'xhci_urb_enqueue()', uses GFP_KERNEL.

Be safe and pass the mem_flags to this function as well.

Fixes: ddba5cd0aeff ("xhci: Use command structures when queuing commands on the command ring")
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20210512080816.866037-4-mathias.nyman@linux.intel.com
[iwamatsu: Adjust context]
Signed-off-by: Nobuhiro Iwamatsu &lt;nobuhiro1.iwamatsu@toshiba.co.jp&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 dda32c00c9a0fa103b5d54ef72c477b7aa993679 upstream.

'xhci_urb_enqueue()' is passed a 'mem_flags' argument, because "URBs may be
submitted in interrupt context" (see comment related to 'usb_submit_urb()'
in 'drivers/usb/core/urb.c')

So this flag should be used in all the calling chain.
Up to now, 'xhci_check_maxpacket()' which is only called from
'xhci_urb_enqueue()', uses GFP_KERNEL.

Be safe and pass the mem_flags to this function as well.

Fixes: ddba5cd0aeff ("xhci: Use command structures when queuing commands on the command ring")
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20210512080816.866037-4-mathias.nyman@linux.intel.com
[iwamatsu: Adjust context]
Signed-off-by: Nobuhiro Iwamatsu &lt;nobuhiro1.iwamatsu@toshiba.co.jp&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: sl811-hcd: improve misleading indentation</title>
<updated>2021-05-22T08:38:29+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2021-03-22T16:42:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9af1581d4976349a7917b59657f83e3bb2ec640c'/>
<id>9af1581d4976349a7917b59657f83e3bb2ec640c</id>
<content type='text'>
commit 8460f6003a1d2633737b89c4f69d6f4c0c7c65a3 upstream.

gcc-11 now warns about a confusingly indented code block:

drivers/usb/host/sl811-hcd.c: In function ‘sl811h_hub_control’:
drivers/usb/host/sl811-hcd.c:1291:9: error: this ‘if’ clause does not guard... [-Werror=misleading-indentation]
 1291 |         if (*(u16*)(buf+2))     /* only if wPortChange is interesting */
      |         ^~
drivers/usb/host/sl811-hcd.c:1295:17: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘if’
 1295 |                 break;

Rewrite this to use a single if() block with the __is_defined() macro.

Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Link: https://lore.kernel.org/r/20210322164244.827589-1-arnd@kernel.org
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 8460f6003a1d2633737b89c4f69d6f4c0c7c65a3 upstream.

gcc-11 now warns about a confusingly indented code block:

drivers/usb/host/sl811-hcd.c: In function ‘sl811h_hub_control’:
drivers/usb/host/sl811-hcd.c:1291:9: error: this ‘if’ clause does not guard... [-Werror=misleading-indentation]
 1291 |         if (*(u16*)(buf+2))     /* only if wPortChange is interesting */
      |         ^~
drivers/usb/host/sl811-hcd.c:1295:17: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘if’
 1295 |                 break;

Rewrite this to use a single if() block with the __is_defined() macro.

Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Link: https://lore.kernel.org/r/20210322164244.827589-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: xhci: Increase timeout for HC halt</title>
<updated>2021-05-22T08:38:29+00:00</updated>
<author>
<name>Maximilian Luz</name>
<email>luzmaximilian@gmail.com</email>
</author>
<published>2021-05-12T08:08:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=72b08f62a6b657fa1c8fb5598e9cb1849dbfb9e5'/>
<id>72b08f62a6b657fa1c8fb5598e9cb1849dbfb9e5</id>
<content type='text'>
commit ca09b1bea63ab83f4cca3a2ae8bc4f597ec28851 upstream.

On some devices (specifically the SC8180x based Surface Pro X with
QCOM04A6) HC halt / xhci_halt() times out during boot. Manually binding
the xhci-hcd driver at some point later does not exhibit this behavior.
To work around this, double XHCI_MAX_HALT_USEC, which also resolves this
issue.

Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Maximilian Luz &lt;luzmaximilian@gmail.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20210512080816.866037-5-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 ca09b1bea63ab83f4cca3a2ae8bc4f597ec28851 upstream.

On some devices (specifically the SC8180x based Surface Pro X with
QCOM04A6) HC halt / xhci_halt() times out during boot. Manually binding
the xhci-hcd driver at some point later does not exhibit this behavior.
To work around this, double XHCI_MAX_HALT_USEC, which also resolves this
issue.

Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Maximilian Luz &lt;luzmaximilian@gmail.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20210512080816.866037-5-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: fotg210-hcd: Fix an error message</title>
<updated>2021-05-22T08:38:29+00:00</updated>
<author>
<name>Christophe JAILLET</name>
<email>christophe.jaillet@wanadoo.fr</email>
</author>
<published>2021-05-06T20:39:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=39b6e6ca84ef2673ced6e71859cfa0107107ea65'/>
<id>39b6e6ca84ef2673ced6e71859cfa0107107ea65</id>
<content type='text'>
[ Upstream commit a60a34366e0d09ca002c966dd7c43a68c28b1f82 ]

'retval' is known to be -ENODEV here.
This is a hard-coded default error code which is not useful in the error
message. Moreover, another error message is printed at the end of the
error handling path. The corresponding error code (-ENOMEM) is more
informative.

So remove simplify the first error message.

While at it, also remove the useless initialization of 'retval'.

Fixes: 7d50195f6c50 ("usb: host: Faraday fotg210-hcd driver")
Signed-off-by: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
Link: https://lore.kernel.org/r/94531bcff98e46d4f9c20183a90b7f47f699126c.1620333419.git.christophe.jaillet@wanadoo.fr
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 a60a34366e0d09ca002c966dd7c43a68c28b1f82 ]

'retval' is known to be -ENODEV here.
This is a hard-coded default error code which is not useful in the error
message. Moreover, another error message is printed at the end of the
error handling path. The corresponding error code (-ENOMEM) is more
informative.

So remove simplify the first error message.

While at it, also remove the useless initialization of 'retval'.

Fixes: 7d50195f6c50 ("usb: host: Faraday fotg210-hcd driver")
Signed-off-by: Christophe JAILLET &lt;christophe.jaillet@wanadoo.fr&gt;
Link: https://lore.kernel.org/r/94531bcff98e46d4f9c20183a90b7f47f699126c.1620333419.git.christophe.jaillet@wanadoo.fr
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: Improve detection of device initiated wake signal.</title>
<updated>2021-03-17T15:07:21+00:00</updated>
<author>
<name>Mathias Nyman</name>
<email>mathias.nyman@linux.intel.com</email>
</author>
<published>2021-03-11T11:53:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bc06115e1bfd393dd75adce5310e274cb10f5585'/>
<id>bc06115e1bfd393dd75adce5310e274cb10f5585</id>
<content type='text'>
commit 253f588c70f66184b1f3a9bbb428b49bbda73e80 upstream.

A xHC USB 3 port might miss the first wake signal from a USB 3 device
if the port LFPS reveiver isn't enabled fast enough after xHC resume.

xHC host will anyway be resumed by a PME# signal, but will go back to
suspend if no port activity is seen.
The device resends the U3 LFPS wake signal after a 100ms delay, but
by then host is already suspended, starting all over from the
beginning of this issue.

USB 3 specs say U3 wake LFPS signal is sent for max 10ms, then device
needs to delay 100ms before resending the wake.

Don't suspend immediately if port activity isn't detected in resume.
Instead add a retry. If there is no port activity then delay for 120ms,
and re-check for port activity.

Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20210311115353.2137560-3-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 253f588c70f66184b1f3a9bbb428b49bbda73e80 upstream.

A xHC USB 3 port might miss the first wake signal from a USB 3 device
if the port LFPS reveiver isn't enabled fast enough after xHC resume.

xHC host will anyway be resumed by a PME# signal, but will go back to
suspend if no port activity is seen.
The device resends the U3 LFPS wake signal after a 100ms delay, but
by then host is already suspended, starting all over from the
beginning of this issue.

USB 3 specs say U3 wake LFPS signal is sent for max 10ms, then device
needs to delay 100ms before resending the wake.

Don't suspend immediately if port activity isn't detected in resume.
Instead add a retry. If there is no port activity then delay for 120ms,
and re-check for port activity.

Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20210311115353.2137560-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xhci: make sure TRB is fully written before giving it to the controller</title>
<updated>2021-01-30T12:25:56+00:00</updated>
<author>
<name>Mathias Nyman</name>
<email>mathias.nyman@linux.intel.com</email>
</author>
<published>2021-01-15T16:19:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5eaa0aa86cc280105d99c391c26aac5f2b549ed9'/>
<id>5eaa0aa86cc280105d99c391c26aac5f2b549ed9</id>
<content type='text'>
commit 576667bad341516edc4e18eb85acb0a2b4c9c9d9 upstream.

Once the command ring doorbell is rung the xHC controller will parse all
command TRBs on the command ring that have the cycle bit set properly.

If the driver just started writing the next command TRB to the ring when
hardware finished the previous TRB, then HW might fetch an incomplete TRB
as long as its cycle bit set correctly.

A command TRB is 16 bytes (128 bits) long.
Driver writes the command TRB in four 32 bit chunks, with the chunk
containing the cycle bit last. This does however not guarantee that
chunks actually get written in that order.

This was detected in stress testing when canceling URBs with several
connected USB devices.
Two consecutive "Set TR Dequeue pointer" commands got queued right
after each other, and the second one was only partially written when
the controller parsed it, causing the dequeue pointer to be set
to bogus values. This was seen as error messages:

"Mismatch between completed Set TR Deq Ptr command &amp; xHCI internal state"

Solution is to add a write memory barrier before writing the cycle bit.

Cc: &lt;stable@vger.kernel.org&gt;
Tested-by: Ross Zwisler &lt;zwisler@google.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20210115161907.2875631-2-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 576667bad341516edc4e18eb85acb0a2b4c9c9d9 upstream.

Once the command ring doorbell is rung the xHC controller will parse all
command TRBs on the command ring that have the cycle bit set properly.

If the driver just started writing the next command TRB to the ring when
hardware finished the previous TRB, then HW might fetch an incomplete TRB
as long as its cycle bit set correctly.

A command TRB is 16 bytes (128 bits) long.
Driver writes the command TRB in four 32 bit chunks, with the chunk
containing the cycle bit last. This does however not guarantee that
chunks actually get written in that order.

This was detected in stress testing when canceling URBs with several
connected USB devices.
Two consecutive "Set TR Dequeue pointer" commands got queued right
after each other, and the second one was only partially written when
the controller parsed it, causing the dequeue pointer to be set
to bogus values. This was seen as error messages:

"Mismatch between completed Set TR Deq Ptr command &amp; xHCI internal state"

Solution is to add a write memory barrier before writing the cycle bit.

Cc: &lt;stable@vger.kernel.org&gt;
Tested-by: Ross Zwisler &lt;zwisler@google.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20210115161907.2875631-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ehci: fix EHCI host controller initialization sequence</title>
<updated>2021-01-30T12:25:56+00:00</updated>
<author>
<name>Eugene Korenevsky</name>
<email>ekorenevsky@astralinux.ru</email>
</author>
<published>2021-01-10T17:36:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c2a8cb52e1fe529b9500459548fe389ff911563f'/>
<id>c2a8cb52e1fe529b9500459548fe389ff911563f</id>
<content type='text'>
commit 280a9045bb18833db921b316a5527d2b565e9f2e upstream.

According to EHCI spec, EHCI HC clears USBSTS.HCHalted whenever
USBCMD.RS=1.

However, it is a good practice to wait some time after setting USBCMD.RS
(approximately 100ms) until USBSTS.HCHalted become zero.

Without this waiting, VirtualBox's EHCI virtual HC accidentally hangs
(see BugLink).

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=211095
Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Eugene Korenevsky &lt;ekorenevsky@astralinux.ru&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Link: https://lore.kernel.org/r/20210110173609.GA17313@himera.home
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 280a9045bb18833db921b316a5527d2b565e9f2e upstream.

According to EHCI spec, EHCI HC clears USBSTS.HCHalted whenever
USBCMD.RS=1.

However, it is a good practice to wait some time after setting USBCMD.RS
(approximately 100ms) until USBSTS.HCHalted become zero.

Without this waiting, VirtualBox's EHCI virtual HC accidentally hangs
(see BugLink).

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=211095
Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Eugene Korenevsky &lt;ekorenevsky@astralinux.ru&gt;
Cc: stable &lt;stable@vger.kernel.org&gt;
Link: https://lore.kernel.org/r/20210110173609.GA17313@himera.home
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
</feed>
