<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/thunderbolt, branch linux-6.14.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>thunderbolt: Do not double dequeue a configuration request</title>
<updated>2025-06-10T11:15:58+00:00</updated>
<author>
<name>Sergey Senozhatsky</name>
<email>senozhatsky@chromium.org</email>
</author>
<published>2025-03-27T15:03:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0771bcbe2f6e5d5f263cf466efe571d2754a46da'/>
<id>0771bcbe2f6e5d5f263cf466efe571d2754a46da</id>
<content type='text'>
commit 0f73628e9da1ee39daf5f188190cdbaee5e0c98c upstream.

Some of our devices crash in tb_cfg_request_dequeue():

 general protection fault, probably for non-canonical address 0xdead000000000122

 CPU: 6 PID: 91007 Comm: kworker/6:2 Tainted: G U W 6.6.65
 RIP: 0010:tb_cfg_request_dequeue+0x2d/0xa0
 Call Trace:
 &lt;TASK&gt;
 ? tb_cfg_request_dequeue+0x2d/0xa0
 tb_cfg_request_work+0x33/0x80
 worker_thread+0x386/0x8f0
 kthread+0xed/0x110
 ret_from_fork+0x38/0x50
 ret_from_fork_asm+0x1b/0x30

The circumstances are unclear, however, the theory is that
tb_cfg_request_work() can be scheduled twice for a request:
first time via frame.callback from ring_work() and second
time from tb_cfg_request().  Both times kworkers will execute
tb_cfg_request_dequeue(), which results in double list_del()
from the ctl-&gt;request_queue (the list poison deference hints
at it: 0xdead000000000122).

Do not dequeue requests that don't have TB_CFG_REQUEST_ACTIVE
bit set.

Signed-off-by: Sergey Senozhatsky &lt;senozhatsky@chromium.org&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 0f73628e9da1ee39daf5f188190cdbaee5e0c98c upstream.

Some of our devices crash in tb_cfg_request_dequeue():

 general protection fault, probably for non-canonical address 0xdead000000000122

 CPU: 6 PID: 91007 Comm: kworker/6:2 Tainted: G U W 6.6.65
 RIP: 0010:tb_cfg_request_dequeue+0x2d/0xa0
 Call Trace:
 &lt;TASK&gt;
 ? tb_cfg_request_dequeue+0x2d/0xa0
 tb_cfg_request_work+0x33/0x80
 worker_thread+0x386/0x8f0
 kthread+0xed/0x110
 ret_from_fork+0x38/0x50
 ret_from_fork_asm+0x1b/0x30

The circumstances are unclear, however, the theory is that
tb_cfg_request_work() can be scheduled twice for a request:
first time via frame.callback from ring_work() and second
time from tb_cfg_request().  Both times kworkers will execute
tb_cfg_request_dequeue(), which results in double list_del()
from the ctl-&gt;request_queue (the list poison deference hints
at it: 0xdead000000000122).

Do not dequeue requests that don't have TB_CFG_REQUEST_ACTIVE
bit set.

Signed-off-by: Sergey Senozhatsky &lt;senozhatsky@chromium.org&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>thunderbolt: Do not add non-active NVM if NVM upgrade is disabled for retimer</title>
<updated>2025-05-29T09:12:40+00:00</updated>
<author>
<name>Mika Westerberg</name>
<email>mika.westerberg@linux.intel.com</email>
</author>
<published>2025-03-05T12:56:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=96151386a4c8908070f7be843b9718a18134156a'/>
<id>96151386a4c8908070f7be843b9718a18134156a</id>
<content type='text'>
[ Upstream commit ad79c278e478ca8c1a3bf8e7a0afba8f862a48a1 ]

This is only used to write a new NVM in order to upgrade the retimer
firmware. It does not make sense to expose it if upgrade is disabled.
This also makes it consistent with the router NVM upgrade.

Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&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 ad79c278e478ca8c1a3bf8e7a0afba8f862a48a1 ]

This is only used to write a new NVM in order to upgrade the retimer
firmware. It does not make sense to expose it if upgrade is disabled.
This also makes it consistent with the router NVM upgrade.

Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>thunderbolt: Scan retimers after device router has been enumerated</title>
<updated>2025-05-02T06:02:02+00:00</updated>
<author>
<name>Mika Westerberg</name>
<email>mika.westerberg@linux.intel.com</email>
</author>
<published>2025-03-04T08:53:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=69c3ca6edc20b930636dfecfd9f8f6849979c051'/>
<id>69c3ca6edc20b930636dfecfd9f8f6849979c051</id>
<content type='text'>
[ Upstream commit 75749d2c1d8cef439f8b69fa1f4f36d0fc3193e6 ]

Thomas reported connection issues on AMD system with Pluggable UD-4VPD
dock. After some experiments it looks like the device has some sort of
internal timeout that triggers reconnect. This is completely against the
USB4 spec, as there is no requirement for the host to enumerate the
device right away or even at all.

In Linux case the delay is caused by scanning of retimers on the link so
we can work this around by doing the scanning after the device router
has been enumerated.

Reported-by: Thomas Lynema &lt;lyz27@yahoo.com&gt;
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219748
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&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 75749d2c1d8cef439f8b69fa1f4f36d0fc3193e6 ]

Thomas reported connection issues on AMD system with Pluggable UD-4VPD
dock. After some experiments it looks like the device has some sort of
internal timeout that triggers reconnect. This is completely against the
USB4 spec, as there is no requirement for the host to enumerate the
device right away or even at all.

In Linux case the delay is caused by scanning of retimers on the link so
we can work this around by doing the scanning after the device router
has been enumerated.

Reported-by: Thomas Lynema &lt;lyz27@yahoo.com&gt;
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219748
Reviewed-by: Mario Limonciello &lt;mario.limonciello@amd.com&gt;
Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>thunderbolt: Prevent use-after-free in resume from hibernate</title>
<updated>2025-03-07T12:00:58+00:00</updated>
<author>
<name>Mika Westerberg</name>
<email>mika.westerberg@linux.intel.com</email>
</author>
<published>2025-03-03T17:40:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=502843396ec2a3eb4f58a2e4618a4a85fc5e0f46'/>
<id>502843396ec2a3eb4f58a2e4618a4a85fc5e0f46</id>
<content type='text'>
Kenneth noticed that his laptop crashes randomly when resuming from
hibernate if there is device connected and display tunneled. I was able
to reproduce this as well with the following steps:

  1. Boot the system up, nothing connected.
  2. Connect Thunderbolt 4 dock to the host.
  3. Connect monitor to the Thunderbolt 4 dock.
  4. Verify that there is picture on the screen.
  5. Enter hibernate.
  6. Exit hibernate.
  7. Wait for the system to resume.

  Expectation: System resumes just fine, the connected monitor still
               shows screen.
  Actual result: There is crash during resume, screen is blank.

What happens is that during resume from hibernate we tear down any
existing tunnels created by the boot kernel and this ends up calling
tb_dp_dprx_stop() which calls tb_tunnel_put() dropping the reference
count to zero even though we never called tb_dp_dprx_start() for it (we
never do that for discovery). This makes the discovered DP tunnel memory
to be released and any access after that causes use-after-free and
possible crash.

Fix this so that we only stop DPRX flow if it has been started in the
first place.

Reported-by: Kenneth Crudup &lt;kenny@panix.com&gt;
Closes: https://lore.kernel.org/linux-usb/8e175721-806f-45d6-892a-bd3356af80c9@panix.com/
Cc: stable@vger.kernel.org
Fixes: d6d458d42e1e ("thunderbolt: Handle DisplayPort tunnel activation asynchronously")
Reviewed-by: Yehezkel Bernat &lt;YehezkelShB@gmail.com&gt;
Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Kenneth noticed that his laptop crashes randomly when resuming from
hibernate if there is device connected and display tunneled. I was able
to reproduce this as well with the following steps:

  1. Boot the system up, nothing connected.
  2. Connect Thunderbolt 4 dock to the host.
  3. Connect monitor to the Thunderbolt 4 dock.
  4. Verify that there is picture on the screen.
  5. Enter hibernate.
  6. Exit hibernate.
  7. Wait for the system to resume.

  Expectation: System resumes just fine, the connected monitor still
               shows screen.
  Actual result: There is crash during resume, screen is blank.

What happens is that during resume from hibernate we tear down any
existing tunnels created by the boot kernel and this ends up calling
tb_dp_dprx_stop() which calls tb_tunnel_put() dropping the reference
count to zero even though we never called tb_dp_dprx_start() for it (we
never do that for discovery). This makes the discovered DP tunnel memory
to be released and any access after that causes use-after-free and
possible crash.

Fix this so that we only stop DPRX flow if it has been started in the
first place.

Reported-by: Kenneth Crudup &lt;kenny@panix.com&gt;
Closes: https://lore.kernel.org/linux-usb/8e175721-806f-45d6-892a-bd3356af80c9@panix.com/
Cc: stable@vger.kernel.org
Fixes: d6d458d42e1e ("thunderbolt: Handle DisplayPort tunnel activation asynchronously")
Reviewed-by: Yehezkel Bernat &lt;YehezkelShB@gmail.com&gt;
Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core</title>
<updated>2025-01-28T20:25:12+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2025-01-28T20:25:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2ab002c755bfa88777e3f2db884d531f3010736c'/>
<id>2ab002c755bfa88777e3f2db884d531f3010736c</id>
<content type='text'>
Pull driver core and debugfs updates from Greg KH:
 "Here is the big set of driver core and debugfs updates for 6.14-rc1.

  Included in here is a bunch of driver core, PCI, OF, and platform rust
  bindings (all acked by the different subsystem maintainers), hence the
  merge conflict with the rust tree, and some driver core api updates to
  mark things as const, which will also require some fixups due to new
  stuff coming in through other trees in this merge window.

  There are also a bunch of debugfs updates from Al, and there is at
  least one user that does have a regression with these, but Al is
  working on tracking down the fix for it. In my use (and everyone
  else's linux-next use), it does not seem like a big issue at the
  moment.

  Here's a short list of the things in here:

   - driver core rust bindings for PCI, platform, OF, and some i/o
     functions.

     We are almost at the "write a real driver in rust" stage now,
     depending on what you want to do.

   - misc device rust bindings and a sample driver to show how to use
     them

   - debugfs cleanups in the fs as well as the users of the fs api for
     places where drivers got it wrong or were unnecessarily doing
     things in complex ways.

   - driver core const work, making more of the api take const * for
     different parameters to make the rust bindings easier overall.

   - other small fixes and updates

  All of these have been in linux-next with all of the aforementioned
  merge conflicts, and the one debugfs issue, which looks to be resolved
  "soon""

* tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (95 commits)
  rust: device: Use as_char_ptr() to avoid explicit cast
  rust: device: Replace CString with CStr in property_present()
  devcoredump: Constify 'struct bin_attribute'
  devcoredump: Define 'struct bin_attribute' through macro
  rust: device: Add property_present()
  saner replacement for debugfs_rename()
  orangefs-debugfs: don't mess with -&gt;d_name
  octeontx2: don't mess with -&gt;d_parent or -&gt;d_parent-&gt;d_name
  arm_scmi: don't mess with -&gt;d_parent-&gt;d_name
  slub: don't mess with -&gt;d_name
  sof-client-ipc-flood-test: don't mess with -&gt;d_name
  qat: don't mess with -&gt;d_name
  xhci: don't mess with -&gt;d_iname
  mtu3: don't mess wiht -&gt;d_iname
  greybus/camera - stop messing with -&gt;d_iname
  mediatek: stop messing with -&gt;d_iname
  netdevsim: don't embed file_operations into your structs
  b43legacy: make use of debugfs_get_aux()
  b43: stop embedding struct file_operations into their objects
  carl9170: stop embedding file_operations into their objects
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull driver core and debugfs updates from Greg KH:
 "Here is the big set of driver core and debugfs updates for 6.14-rc1.

  Included in here is a bunch of driver core, PCI, OF, and platform rust
  bindings (all acked by the different subsystem maintainers), hence the
  merge conflict with the rust tree, and some driver core api updates to
  mark things as const, which will also require some fixups due to new
  stuff coming in through other trees in this merge window.

  There are also a bunch of debugfs updates from Al, and there is at
  least one user that does have a regression with these, but Al is
  working on tracking down the fix for it. In my use (and everyone
  else's linux-next use), it does not seem like a big issue at the
  moment.

  Here's a short list of the things in here:

   - driver core rust bindings for PCI, platform, OF, and some i/o
     functions.

     We are almost at the "write a real driver in rust" stage now,
     depending on what you want to do.

   - misc device rust bindings and a sample driver to show how to use
     them

   - debugfs cleanups in the fs as well as the users of the fs api for
     places where drivers got it wrong or were unnecessarily doing
     things in complex ways.

   - driver core const work, making more of the api take const * for
     different parameters to make the rust bindings easier overall.

   - other small fixes and updates

  All of these have been in linux-next with all of the aforementioned
  merge conflicts, and the one debugfs issue, which looks to be resolved
  "soon""

* tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (95 commits)
  rust: device: Use as_char_ptr() to avoid explicit cast
  rust: device: Replace CString with CStr in property_present()
  devcoredump: Constify 'struct bin_attribute'
  devcoredump: Define 'struct bin_attribute' through macro
  rust: device: Add property_present()
  saner replacement for debugfs_rename()
  orangefs-debugfs: don't mess with -&gt;d_name
  octeontx2: don't mess with -&gt;d_parent or -&gt;d_parent-&gt;d_name
  arm_scmi: don't mess with -&gt;d_parent-&gt;d_name
  slub: don't mess with -&gt;d_name
  sof-client-ipc-flood-test: don't mess with -&gt;d_name
  qat: don't mess with -&gt;d_name
  xhci: don't mess with -&gt;d_iname
  mtu3: don't mess wiht -&gt;d_iname
  greybus/camera - stop messing with -&gt;d_iname
  mediatek: stop messing with -&gt;d_iname
  netdevsim: don't embed file_operations into your structs
  b43legacy: make use of debugfs_get_aux()
  b43: stop embedding struct file_operations into their objects
  carl9170: stop embedding file_operations into their objects
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge 6.13-rc7 into driver-core-next</title>
<updated>2025-01-13T05:40:34+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2025-01-13T05:40:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dd19f4116ec330bc985e1a85a66b8dd0f2dca20d'/>
<id>dd19f4116ec330bc985e1a85a66b8dd0f2dca20d</id>
<content type='text'>
We need the debugfs / driver-core fixes in here as well for testing and
to build on top of.

Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We need the debugfs / driver-core fixes in here as well for testing and
to build on top of.

Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>thunderbolt: Expose router DROM through debugfs</title>
<updated>2025-01-05T08:35:03+00:00</updated>
<author>
<name>Mika Westerberg</name>
<email>mika.westerberg@linux.intel.com</email>
</author>
<published>2024-12-21T12:52:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=43d84701d2aa147eab39b529919ffaf35f724bbb'/>
<id>43d84701d2aa147eab39b529919ffaf35f724bbb</id>
<content type='text'>
Router DROM contains information that might be usable for development
and debugging purposes. For example when new entries are added to the
USB4 spec it is useful to be able to look for them without need to
change the kernel.

For this reason expose the DROM through debugfs.

Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Router DROM contains information that might be usable for development
and debugging purposes. For example when new entries are added to the
USB4 spec it is useful to be able to look for them without need to
change the kernel.

For this reason expose the DROM through debugfs.

Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>driver core: Constify API device_find_child() and adapt for various usages</title>
<updated>2025-01-03T10:19:35+00:00</updated>
<author>
<name>Zijun Hu</name>
<email>quic_zijuhu@quicinc.com</email>
</author>
<published>2024-12-24T13:05:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f1e8bf56320a7fb32095b6c51b707459361b403b'/>
<id>f1e8bf56320a7fb32095b6c51b707459361b403b</id>
<content type='text'>
Constify the following API:
struct device *device_find_child(struct device *dev, void *data,
		int (*match)(struct device *dev, void *data));
To :
struct device *device_find_child(struct device *dev, const void *data,
                                 device_match_t match);
typedef int (*device_match_t)(struct device *dev, const void *data);
with the following reasons:

- Protect caller's match data @*data which is for comparison and lookup
  and the API does not actually need to modify @*data.

- Make the API's parameters (@match)() and @data have the same type as
  all of other device finding APIs (bus|class|driver)_find_device().

- All kinds of existing device match functions can be directly taken
  as the API's argument, they were exported by driver core.

Constify the API and adapt for various existing usages.

BTW, various subsystem changes are squashed into this commit to meet
'git bisect' requirement, and this commit has the minimal and simplest
changes to complement squashing shortcoming, and that may bring extra
code improvement.

Reviewed-by: Alison Schofield &lt;alison.schofield@intel.com&gt;
Reviewed-by: Takashi Sakamoto &lt;o-takashi@sakamocchi.jp&gt;
Acked-by: Uwe Kleine-König &lt;ukleinek@kernel.org&gt; # for drivers/pwm
Signed-off-by: Zijun Hu &lt;quic_zijuhu@quicinc.com&gt;
Reviewed-by: Jonathan Cameron &lt;Jonathan.Cameron@huawei.com&gt;
Reviewed-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-4-6623037414d4@quicinc.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>
Constify the following API:
struct device *device_find_child(struct device *dev, void *data,
		int (*match)(struct device *dev, void *data));
To :
struct device *device_find_child(struct device *dev, const void *data,
                                 device_match_t match);
typedef int (*device_match_t)(struct device *dev, const void *data);
with the following reasons:

- Protect caller's match data @*data which is for comparison and lookup
  and the API does not actually need to modify @*data.

- Make the API's parameters (@match)() and @data have the same type as
  all of other device finding APIs (bus|class|driver)_find_device().

- All kinds of existing device match functions can be directly taken
  as the API's argument, they were exported by driver core.

Constify the API and adapt for various existing usages.

BTW, various subsystem changes are squashed into this commit to meet
'git bisect' requirement, and this commit has the minimal and simplest
changes to complement squashing shortcoming, and that may bring extra
code improvement.

Reviewed-by: Alison Schofield &lt;alison.schofield@intel.com&gt;
Reviewed-by: Takashi Sakamoto &lt;o-takashi@sakamocchi.jp&gt;
Acked-by: Uwe Kleine-König &lt;ukleinek@kernel.org&gt; # for drivers/pwm
Signed-off-by: Zijun Hu &lt;quic_zijuhu@quicinc.com&gt;
Reviewed-by: Jonathan Cameron &lt;Jonathan.Cameron@huawei.com&gt;
Reviewed-by: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Link: https://lore.kernel.org/r/20241224-const_dfc_done-v5-4-6623037414d4@quicinc.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>thunderbolt: Handle DisplayPort tunnel activation asynchronously</title>
<updated>2025-01-03T09:50:09+00:00</updated>
<author>
<name>Mika Westerberg</name>
<email>mika.westerberg@linux.intel.com</email>
</author>
<published>2024-08-20T05:56:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d6d458d42e1e1544a18f37f1d5c840e00d5261b9'/>
<id>d6d458d42e1e1544a18f37f1d5c840e00d5261b9</id>
<content type='text'>
Sometimes setting up a DisplayPort tunnel may take quite long time. The
reason is that the graphics driver (DPRX) is expected to issue read of
certain monitor capabilities over the AUX channel and the "suggested"
timeout from VESA is 5 seconds. If there is no graphics driver loaded
this does not happen and currently we timeout and tear the tunnel down.
The reason for this is that at least Intel discrete USB4 controllers do
not send plug/unplug events about whether the DisplayPort cable from the
GPU to the controller is connected or not, so in order to "release" the
DisplayPort OUT adapter (the one that has monitor connected) we must
tear the tunnel down after this timeout has been elapsed.

In typical cases there is always graphics driver loaded, and also all
the cables are connected but for instance in Intel graphics CI they only
load the graphics driver after the system is fully booted up. This
makes the driver to tear down the DisplayPort tunnel. To help this case
we allow passing bigger or indefinite timeout through a new module
parameter (dprx_timeout). To keep the driver bit more responsive during
that time we change the way DisplayPort tunnels get activated. We first
do the normal tunnel setup and then run the polling of DPRX capabilities
read completion in a separate worker. This also makes the driver to
accept bandwidth requests to already established DisplayPort tunnels
more responsive.

If the tunnel still fails to establish we will tear it down and remove
the DisplayPort IN adapter from the dp_resource list to avoid using it
again (unless we get hotplug to that adapter).

Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Sometimes setting up a DisplayPort tunnel may take quite long time. The
reason is that the graphics driver (DPRX) is expected to issue read of
certain monitor capabilities over the AUX channel and the "suggested"
timeout from VESA is 5 seconds. If there is no graphics driver loaded
this does not happen and currently we timeout and tear the tunnel down.
The reason for this is that at least Intel discrete USB4 controllers do
not send plug/unplug events about whether the DisplayPort cable from the
GPU to the controller is connected or not, so in order to "release" the
DisplayPort OUT adapter (the one that has monitor connected) we must
tear the tunnel down after this timeout has been elapsed.

In typical cases there is always graphics driver loaded, and also all
the cables are connected but for instance in Intel graphics CI they only
load the graphics driver after the system is fully booted up. This
makes the driver to tear down the DisplayPort tunnel. To help this case
we allow passing bigger or indefinite timeout through a new module
parameter (dprx_timeout). To keep the driver bit more responsive during
that time we change the way DisplayPort tunnels get activated. We first
do the normal tunnel setup and then run the polling of DPRX capabilities
read completion in a separate worker. This also makes the driver to
accept bandwidth requests to already established DisplayPort tunnels
more responsive.

If the tunnel still fails to establish we will tear it down and remove
the DisplayPort IN adapter from the dp_resource list to avoid using it
again (unless we get hotplug to that adapter).

Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>thunderbolt: Rework tb_tunnel_consumed_bandwidth()</title>
<updated>2025-01-03T09:50:08+00:00</updated>
<author>
<name>Mika Westerberg</name>
<email>mika.westerberg@linux.intel.com</email>
</author>
<published>2024-08-26T12:04:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a70cd9cddeb2836377547efa9d76b391556ae687'/>
<id>a70cd9cddeb2836377547efa9d76b391556ae687</id>
<content type='text'>
Rework to avoid the goto as it only makes it confusing. Move logging to
happen at the end so we can see all the tunnels this is being called.

Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Rework to avoid the goto as it only makes it confusing. Move logging to
happen at the end so we can see all the tunnels this is being called.

Signed-off-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
