<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/usb/host, branch v4.19.239</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: add pci device support for Aspeed platforms</title>
<updated>2022-04-15T12:15:01+00:00</updated>
<author>
<name>Neal Liu</name>
<email>neal_liu@aspeedtech.com</email>
</author>
<published>2022-02-08T10:16:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d02d56b58cd3eb3226f8a4444a6e9424218b2e2a'/>
<id>d02d56b58cd3eb3226f8a4444a6e9424218b2e2a</id>
<content type='text'>
[ Upstream commit c3c9cee592828528fd228b01d312c7526c584a42 ]

Enable Aspeed quirks in commit 7f2d73788d90 ("usb: ehci:
handshake CMD_RUN instead of STS_HALT") to support Aspeed
ehci-pci device.

Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Neal Liu &lt;neal_liu@aspeedtech.com&gt;
Link: https://lore.kernel.org/r/20220208101657.76459-1-neal_liu@aspeedtech.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 c3c9cee592828528fd228b01d312c7526c584a42 ]

Enable Aspeed quirks in commit 7f2d73788d90 ("usb: ehci:
handshake CMD_RUN instead of STS_HALT") to support Aspeed
ehci-pci device.

Acked-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Neal Liu &lt;neal_liu@aspeedtech.com&gt;
Link: https://lore.kernel.org/r/20220208101657.76459-1-neal_liu@aspeedtech.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: make xhci_handshake timeout for xhci_reset() adjustable</title>
<updated>2022-04-15T12:14:38+00:00</updated>
<author>
<name>Mathias Nyman</name>
<email>mathias.nyman@linux.intel.com</email>
</author>
<published>2022-03-03T11:08:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1c713660c51f3bc64fc1c709ba2bfb358551f3da'/>
<id>1c713660c51f3bc64fc1c709ba2bfb358551f3da</id>
<content type='text'>
commit 14073ce951b5919da450022c050772902f24f054 upstream.

xhci_reset() timeout was increased from 250ms to 10 seconds in order to
give Renesas 720201 xHC enough time to get ready in probe.

xhci_reset() is called with interrupts disabled in other places, and
waiting for 10 seconds there is not acceptable.

Add a timeout parameter to xhci_reset(), and adjust it back to 250ms
when called from xhci_stop() or xhci_shutdown() where interrupts are
disabled, and successful reset isn't that critical.
This solves issues when deactivating host mode on platforms like SM8450.

For now don't change the timeout if xHC is reset in xhci_resume().
No issues are reported for it, and we need the reset to succeed.
Locking around that reset needs to be revisited later.

Additionally change the signed integer timeout parameter in
xhci_handshake() to a u64 to match the timeout value we pass to
readl_poll_timeout_atomic()

Fixes: 22ceac191211 ("xhci: Increase reset timeout for Renesas 720201 host.")
Cc: stable@vger.kernel.org
Reported-by: Sergey Shtylyov &lt;s.shtylyov@omp.ru&gt;
Reported-by: Pavan Kondeti &lt;quic_pkondeti@quicinc.com&gt;
Tested-by: Pavan Kondeti &lt;quic_pkondeti@quicinc.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220303110903.1662404-2-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 14073ce951b5919da450022c050772902f24f054 upstream.

xhci_reset() timeout was increased from 250ms to 10 seconds in order to
give Renesas 720201 xHC enough time to get ready in probe.

xhci_reset() is called with interrupts disabled in other places, and
waiting for 10 seconds there is not acceptable.

Add a timeout parameter to xhci_reset(), and adjust it back to 250ms
when called from xhci_stop() or xhci_shutdown() where interrupts are
disabled, and successful reset isn't that critical.
This solves issues when deactivating host mode on platforms like SM8450.

For now don't change the timeout if xHC is reset in xhci_resume().
No issues are reported for it, and we need the reset to succeed.
Locking around that reset needs to be revisited later.

Additionally change the signed integer timeout parameter in
xhci_handshake() to a u64 to match the timeout value we pass to
readl_poll_timeout_atomic()

Fixes: 22ceac191211 ("xhci: Increase reset timeout for Renesas 720201 host.")
Cc: stable@vger.kernel.org
Reported-by: Sergey Shtylyov &lt;s.shtylyov@omp.ru&gt;
Reported-by: Pavan Kondeti &lt;quic_pkondeti@quicinc.com&gt;
Tested-by: Pavan Kondeti &lt;quic_pkondeti@quicinc.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220303110903.1662404-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xhci: Prevent futile URB re-submissions due to incorrect return value.</title>
<updated>2022-03-02T10:38:18+00:00</updated>
<author>
<name>Hongyu Xie</name>
<email>xiehongyu1@kylinos.cn</email>
</author>
<published>2022-02-15T12:33:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4cf9a3da2b555f77a9a8956a754ac9e3c53c3384'/>
<id>4cf9a3da2b555f77a9a8956a754ac9e3c53c3384</id>
<content type='text'>
commit 243a1dd7ba48c120986dd9e66fee74bcb7751034 upstream.

The -ENODEV return value from xhci_check_args() is incorrectly changed
to -EINVAL in a couple places before propagated further.

xhci_check_args() returns 4 types of value, -ENODEV, -EINVAL, 1 and 0.
xhci_urb_enqueue and xhci_check_streams_endpoint return -EINVAL if
the return value of xhci_check_args &lt;= 0.
This causes problems for example r8152_submit_rx, calling usb_submit_urb
in drivers/net/usb/r8152.c.
r8152_submit_rx will never get -ENODEV after submiting an urb when xHC
is halted because xhci_urb_enqueue returns -EINVAL in the very beginning.

[commit message and header edit -Mathias]

Fixes: 203a86613fb3 ("xhci: Avoid NULL pointer deref when host dies.")
Cc: stable@vger.kernel.org
Signed-off-by: Hongyu Xie &lt;xiehongyu1@kylinos.cn&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220215123320.1253947-3-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 243a1dd7ba48c120986dd9e66fee74bcb7751034 upstream.

The -ENODEV return value from xhci_check_args() is incorrectly changed
to -EINVAL in a couple places before propagated further.

xhci_check_args() returns 4 types of value, -ENODEV, -EINVAL, 1 and 0.
xhci_urb_enqueue and xhci_check_streams_endpoint return -EINVAL if
the return value of xhci_check_args &lt;= 0.
This causes problems for example r8152_submit_rx, calling usb_submit_urb
in drivers/net/usb/r8152.c.
r8152_submit_rx will never get -ENODEV after submiting an urb when xHC
is halted because xhci_urb_enqueue returns -EINVAL in the very beginning.

[commit message and header edit -Mathias]

Fixes: 203a86613fb3 ("xhci: Avoid NULL pointer deref when host dies.")
Cc: stable@vger.kernel.org
Signed-off-by: Hongyu Xie &lt;xiehongyu1@kylinos.cn&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220215123320.1253947-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xhci: re-initialize the HC during resume if HCE was set</title>
<updated>2022-03-02T10:38:18+00:00</updated>
<author>
<name>Puma Hsu</name>
<email>pumahsu@google.com</email>
</author>
<published>2022-02-15T12:33:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=792e96856d84a9d6dbe0579764e4bcb47cb8b776'/>
<id>792e96856d84a9d6dbe0579764e4bcb47cb8b776</id>
<content type='text'>
commit 8b328f8002bcf29ef517ee4bf234e09aabec4d2e upstream.

When HCE(Host Controller Error) is set, it means an internal
error condition has been detected. Software needs to re-initialize
the HC, so add this check in xhci resume.

Cc: stable@vger.kernel.org
Signed-off-by: Puma Hsu &lt;pumahsu@google.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220215123320.1253947-2-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 8b328f8002bcf29ef517ee4bf234e09aabec4d2e upstream.

When HCE(Host Controller Error) is set, it means an internal
error condition has been detected. Software needs to re-initialize
the HC, so add this check in xhci resume.

Cc: stable@vger.kernel.org
Signed-off-by: Puma Hsu &lt;pumahsu@google.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20220215123320.1253947-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: uhci: add aspeed ast2600 uhci support</title>
<updated>2022-01-27T08:04:24+00:00</updated>
<author>
<name>Neal Liu</name>
<email>neal_liu@aspeedtech.com</email>
</author>
<published>2021-11-26T10:00:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=460f723de1281398da55cdb24f06e468efbd244b'/>
<id>460f723de1281398da55cdb24f06e468efbd244b</id>
<content type='text'>
[ Upstream commit 554abfe2eadec97d12c71d4a69da1518478f69eb ]

Enable ast2600 uhci quirks.

Signed-off-by: Neal Liu &lt;neal_liu@aspeedtech.com&gt;
Link: https://lore.kernel.org/r/20211126100021.2331024-1-neal_liu@aspeedtech.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 554abfe2eadec97d12c71d4a69da1518478f69eb ]

Enable ast2600 uhci quirks.

Signed-off-by: Neal Liu &lt;neal_liu@aspeedtech.com&gt;
Link: https://lore.kernel.org/r/20211126100021.2331024-1-neal_liu@aspeedtech.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: Fresco FL1100 controller should not have BROKEN_MSI quirk set.</title>
<updated>2022-01-05T11:34:59+00:00</updated>
<author>
<name>Mathias Nyman</name>
<email>mathias.nyman@linux.intel.com</email>
</author>
<published>2021-12-21T11:28:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a3d19b025a4d21705570b54ba4478baa9fd8cd8b'/>
<id>a3d19b025a4d21705570b54ba4478baa9fd8cd8b</id>
<content type='text'>
commit e4844092581ceec22489b66c42edc88bc6079783 upstream.

The Fresco Logic FL1100 controller needs the TRUST_TX_LENGTH quirk like
other Fresco controllers, but should not have the BROKEN_MSI quirks set.

BROKEN_MSI quirk causes issues in detecting usb drives connected to docks
with this FL1100 controller.
The BROKEN_MSI flag was apparently accidentally set together with the
TRUST_TX_LENGTH quirk

Original patch went to stable so this should go there as well.

Fixes: ea0f69d82119 ("xhci: Enable trust tx length quirk for Fresco FL11 USB controller")
Cc: stable@vger.kernel.org
cc: Nikolay Martynov &lt;mar.kolya@gmail.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20211221112825.54690-2-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 e4844092581ceec22489b66c42edc88bc6079783 upstream.

The Fresco Logic FL1100 controller needs the TRUST_TX_LENGTH quirk like
other Fresco controllers, but should not have the BROKEN_MSI quirks set.

BROKEN_MSI quirk causes issues in detecting usb drives connected to docks
with this FL1100 controller.
The BROKEN_MSI flag was apparently accidentally set together with the
TRUST_TX_LENGTH quirk

Original patch went to stable so this should go there as well.

Fixes: ea0f69d82119 ("xhci: Enable trust tx length quirk for Fresco FL11 USB controller")
Cc: stable@vger.kernel.org
cc: Nikolay Martynov &lt;mar.kolya@gmail.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20211221112825.54690-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xhci: avoid race between disable slot command and host runtime suspend</title>
<updated>2021-12-14T09:18:08+00:00</updated>
<author>
<name>Mathias Nyman</name>
<email>mathias.nyman@linux.intel.com</email>
</author>
<published>2021-12-10T14:17:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cc7c2818c71ebace207df40cc586c8c74e3d1a59'/>
<id>cc7c2818c71ebace207df40cc586c8c74e3d1a59</id>
<content type='text'>
commit 7faac1953ed1f658f719cdf7bb7303fa5eef822c upstream.

Make xhci_disable_slot() synchronous, thus ensuring it, and
xhci_free_dev() calling it return after xHC controller completes
the disable slot command.

Otherwise the roothub and xHC host may runtime suspend, and clear the
command ring while the disable slot command is being processed.

This causes a command completion mismatch as the completion event can't
be mapped to the correct command.
Command ring gets out of sync and commands time out.
Driver finally assumes host is unresponsive and bails out.

usb 2-4: USB disconnect, device number 10
xhci_hcd 0000:00:0d.0: ERROR mismatched command completion event
...
xhci_hcd 0000:00:0d.0: xHCI host controller not responding, assume dead
xhci_hcd 0000:00:0d.0: HC died; cleaning up

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/20211210141735.1384209-3-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 7faac1953ed1f658f719cdf7bb7303fa5eef822c upstream.

Make xhci_disable_slot() synchronous, thus ensuring it, and
xhci_free_dev() calling it return after xHC controller completes
the disable slot command.

Otherwise the roothub and xHC host may runtime suspend, and clear the
command ring while the disable slot command is being processed.

This causes a command completion mismatch as the completion event can't
be mapped to the correct command.
Command ring gets out of sync and commands time out.
Driver finally assumes host is unresponsive and bails out.

usb 2-4: USB disconnect, device number 10
xhci_hcd 0000:00:0d.0: ERROR mismatched command completion event
...
xhci_hcd 0000:00:0d.0: xHCI host controller not responding, assume dead
xhci_hcd 0000:00:0d.0: HC died; cleaning up

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/20211210141735.1384209-3-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xhci: Remove CONFIG_USB_DEFAULT_PERSIST to prevent xHCI from runtime suspending</title>
<updated>2021-12-14T09:18:08+00:00</updated>
<author>
<name>Kai-Heng Feng</name>
<email>kai.heng.feng@canonical.com</email>
</author>
<published>2021-12-10T14:17:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5054e9aecffa55f4798bde75917003ed965fdb77'/>
<id>5054e9aecffa55f4798bde75917003ed965fdb77</id>
<content type='text'>
commit 811ae81320da53a5670c36970cefacca8519f90e upstream.

When the xHCI is quirked with XHCI_RESET_ON_RESUME, runtime resume
routine also resets the controller.

This is bad for USB drivers without reset_resume callback, because
there's no subsequent call of usb_dev_complete() -&gt;
usb_resume_complete() to force rebinding the driver to the device. For
instance, btusb device stops working after xHCI controller is runtime
resumed, if the controlled is quirked with XHCI_RESET_ON_RESUME.

So always take XHCI_RESET_ON_RESUME into account to solve the issue.

Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20211210141735.1384209-2-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 811ae81320da53a5670c36970cefacca8519f90e upstream.

When the xHCI is quirked with XHCI_RESET_ON_RESUME, runtime resume
routine also resets the controller.

This is bad for USB drivers without reset_resume callback, because
there's no subsequent call of usb_dev_complete() -&gt;
usb_resume_complete() to force rebinding the driver to the device. For
instance, btusb device stops working after xHCI controller is runtime
resumed, if the controlled is quirked with XHCI_RESET_ON_RESUME.

So always take XHCI_RESET_ON_RESUME into account to solve the issue.

Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Kai-Heng Feng &lt;kai.heng.feng@canonical.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20211210141735.1384209-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xhci: Fix commad ring abort, write all 64 bits to CRCR register.</title>
<updated>2021-12-08T07:50:14+00:00</updated>
<author>
<name>Mathias Nyman</name>
<email>mathias.nyman@linux.intel.com</email>
</author>
<published>2021-11-26T12:23:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=abba418a9c73dcffecbe19ef93c7ae5d2e8e38d3'/>
<id>abba418a9c73dcffecbe19ef93c7ae5d2e8e38d3</id>
<content type='text'>
commit 09f736aa95476631227d2dc0e6b9aeee1ad7ed58 upstream.

Turns out some xHC controllers require all 64 bits in the CRCR register
to be written to execute a command abort.

The lower 32 bits containing the command abort bit is written first.
In case the command ring stops before we write the upper 32 bits then
hardware may use these upper bits to set the commnd ring dequeue pointer.

Solve this by making sure the upper 32 bits contain a valid command
ring dequeue pointer.

The original patch that only wrote the first 32 to stop the ring went
to stable, so this fix should go there as well.

Fixes: ff0e50d3564f ("xhci: Fix command ring pointer corruption while aborting a command")
Cc: stable@vger.kernel.org
Tested-by: Pavankumar Kondeti &lt;quic_pkondeti@quicinc.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20211126122340.1193239-2-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 09f736aa95476631227d2dc0e6b9aeee1ad7ed58 upstream.

Turns out some xHC controllers require all 64 bits in the CRCR register
to be written to execute a command abort.

The lower 32 bits containing the command abort bit is written first.
In case the command ring stops before we write the upper 32 bits then
hardware may use these upper bits to set the commnd ring dequeue pointer.

Solve this by making sure the upper 32 bits contain a valid command
ring dequeue pointer.

The original patch that only wrote the first 32 to stop the ring went
to stable, so this fix should go there as well.

Fixes: ff0e50d3564f ("xhci: Fix command ring pointer corruption while aborting a command")
Cc: stable@vger.kernel.org
Tested-by: Pavankumar Kondeti &lt;quic_pkondeti@quicinc.com&gt;
Signed-off-by: Mathias Nyman &lt;mathias.nyman@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20211126122340.1193239-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>usb: max-3421: Use driver data instead of maintaining a list of bound devices</title>
<updated>2021-11-26T10:36:24+00:00</updated>
<author>
<name>Uwe Kleine-König</name>
<email>u.kleine-koenig@pengutronix.de</email>
</author>
<published>2021-10-18T20:40:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=62b4c59eb2726d9411d16f9ffe55131272ceb3c9'/>
<id>62b4c59eb2726d9411d16f9ffe55131272ceb3c9</id>
<content type='text'>
commit fc153aba3ef371d0d76eb88230ed4e0dee5b38f2 upstream.

Instead of maintaining a single-linked list of devices that must be
searched linearly in .remove() just use spi_set_drvdata() to remember the
link between the spi device and the driver struct. Then the global list
and the next member can be dropped.

This simplifies the driver, reduces the memory footprint and the time to
search the list. Also it makes obvious that there is always a corresponding
driver struct for a given device in .remove(), so the error path for
!max3421_hcd can be dropped, too.

As a side effect this fixes a data inconsistency when .probe() races with
itself for a second max3421 device in manipulating max3421_hcd_list. A
similar race is fixed in .remove(), too.

Fixes: 2d53139f3162 ("Add support for using a MAX3421E chip as a host driver.")
Signed-off-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Link: https://lore.kernel.org/r/20211018204028.2914597-1-u.kleine-koenig@pengutronix.de
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 fc153aba3ef371d0d76eb88230ed4e0dee5b38f2 upstream.

Instead of maintaining a single-linked list of devices that must be
searched linearly in .remove() just use spi_set_drvdata() to remember the
link between the spi device and the driver struct. Then the global list
and the next member can be dropped.

This simplifies the driver, reduces the memory footprint and the time to
search the list. Also it makes obvious that there is always a corresponding
driver struct for a given device in .remove(), so the error path for
!max3421_hcd can be dropped, too.

As a side effect this fixes a data inconsistency when .probe() races with
itself for a second max3421 device in manipulating max3421_hcd_list. A
similar race is fixed in .remove(), too.

Fixes: 2d53139f3162 ("Add support for using a MAX3421E chip as a host driver.")
Signed-off-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Link: https://lore.kernel.org/r/20211018204028.2914597-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
