linux.git/drivers/usb/typec/altmodes, branch v6.16 Linux kernel source tree usb: typec: displayport: Fix potential deadlock 2025-06-24T14:43:15+00:00 Andrei Kuchynski akuchynski@chromium.org 2025-06-24T13:32:46+00:00 099cf1fbb8afc3771f408109f62bdec66f85160e The deadlock can occur due to a recursive lock acquisition of `cros_typec_altmode_data::mutex`. The call chain is as follows: 1. cros_typec_altmode_work() acquires the mutex 2. typec_altmode_vdm() -> dp_altmode_vdm() -> 3. typec_altmode_exit() -> cros_typec_altmode_exit() 4. cros_typec_altmode_exit() attempts to acquire the mutex again To prevent this, defer the `typec_altmode_exit()` call by scheduling it rather than calling it directly from within the mutex-protected context. Cc: stable <stable@kernel.org> Fixes: b4b38ffb38c9 ("usb: typec: displayport: Receive DP Status Update NAK request exit dp altmode") Signed-off-by: Andrei Kuchynski <akuchynski@chromium.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20250624133246.3936737-1-akuchynski@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The deadlock can occur due to a recursive lock acquisition of
`cros_typec_altmode_data::mutex`.
The call chain is as follows:
1. cros_typec_altmode_work() acquires the mutex
2. typec_altmode_vdm() -> dp_altmode_vdm() ->
3. typec_altmode_exit() -> cros_typec_altmode_exit()
4. cros_typec_altmode_exit() attempts to acquire the mutex again

To prevent this, defer the `typec_altmode_exit()` call by scheduling
it rather than calling it directly from within the mutex-protected
context.

Cc: stable <stable@kernel.org>
Fixes: b4b38ffb38c9 ("usb: typec: displayport: Receive DP Status Update NAK request exit dp altmode")
Signed-off-by: Andrei Kuchynski <akuchynski@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20250624133246.3936737-1-akuchynski@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: altmodes/displayport: do not index invalid pin_assignments 2025-06-24T14:42:55+00:00 RD Babiera rdbabiera@google.com 2025-06-18T22:49:42+00:00 af4db5a35a4ef7a68046883bfd12468007db38f1 A poorly implemented DisplayPort Alt Mode port partner can indicate that its pin assignment capabilities are greater than the maximum value, DP_PIN_ASSIGN_F. In this case, calls to pin_assignment_show will cause a BRK exception due to an out of bounds array access. Prevent for loop in pin_assignment_show from accessing invalid values in pin_assignments by adding DP_PIN_ASSIGN_MAX value in typec_dp.h and using i < DP_PIN_ASSIGN_MAX as a loop condition. Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode") Cc: stable <stable@kernel.org> Signed-off-by: RD Babiera <rdbabiera@google.com> Reviewed-by: Badhri Jagan Sridharan <badhri@google.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20250618224943.3263103-2-rdbabiera@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
A poorly implemented DisplayPort Alt Mode port partner can indicate
that its pin assignment capabilities are greater than the maximum
value, DP_PIN_ASSIGN_F. In this case, calls to pin_assignment_show
will cause a BRK exception due to an out of bounds array access.

Prevent for loop in pin_assignment_show from accessing
invalid values in pin_assignments by adding DP_PIN_ASSIGN_MAX
value in typec_dp.h and using i < DP_PIN_ASSIGN_MAX as a loop
condition.

Fixes: 0e3bb7d6894d ("usb: typec: Add driver for DisplayPort alternate mode")
Cc: stable <stable@kernel.org>
Signed-off-by: RD Babiera <rdbabiera@google.com>
Reviewed-by: Badhri Jagan Sridharan <badhri@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20250618224943.3263103-2-rdbabiera@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: displayport: Receive DP Status Update NAK request exit dp altmode 2025-04-11T14:08:32+00:00 Jos Wang joswang@lenovo.com 2025-02-09T07:19:26+00:00 b4b38ffb38c91afd4dc387608db26f6fc34ed40b Although some Type-C DRD devices that do not support the DP Sink function (such as Huawei Mate 40Pro), the Source Port initiates Enter Mode CMD, but the device responds to Enter Mode ACK, the Source port then initiates DP Status Update CMD, and the device responds to DP Status Update NAK. As PD2.0 spec ("6.4.4.3.4 Enter Mode Command")，A DR_Swap Message Shall Not be sent during Modal Operation between the Port Partners. At this time, the source port initiates DR_Swap message through the "echo device > /sys/class/typec/port0/data_role" command to switch the data role from host to device. The device will initiate a Hard Reset for recovery, resulting in the failure of data role swap. Therefore, when DP Status Update NAK is received, Exit Mode CMD is initiated to exit the currently entered DP altmode. Signed-off-by: Jos Wang <joswang@lenovo.com> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20250209071926.69625-1-joswang1221@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Although some Type-C DRD devices that do not support the DP Sink
function (such as Huawei Mate 40Pro), the Source Port initiates
Enter Mode CMD, but the device responds to Enter Mode ACK, the
Source port then initiates DP Status Update CMD, and the device
responds to DP Status Update NAK.

As PD2.0 spec ("6.4.4.3.4 Enter Mode Command")，A DR_Swap Message
Shall Not be sent during Modal Operation between the Port Partners.
At this time, the source port initiates DR_Swap message through the
"echo device > /sys/class/typec/port0/data_role" command to switch
the data role from host to device. The device will initiate a Hard
Reset for recovery, resulting in the failure of data role swap.

Therefore, when DP Status Update NAK is received, Exit Mode CMD is
initiated to exit the currently entered DP altmode.

Signed-off-by: Jos Wang <joswang@lenovo.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20250209071926.69625-1-joswang1221@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: thunderbolt: Remove IS_ERR check for plug 2025-02-03T15:30:51+00:00 Benson Leung bleung@chromium.org 2025-01-24T19:40:38+00:00 9682c35ff6ecd76d9462d4749b8b413d3e8e605e Fixes these Smatch static checker warnings: drivers/usb/typec/altmodes/thunderbolt.c:354 tbt_ready() warn: 'plug' is not an error pointer Fixes: 100e25738659 ("usb: typec: Add driver for Thunderbolt 3 Alternate Mode") Signed-off-by: Benson Leung <bleung@chromium.org> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/Z5PstnlA52Z1F2SU@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Fixes these Smatch static checker warnings:
drivers/usb/typec/altmodes/thunderbolt.c:354 tbt_ready() warn: 'plug' is not an error pointer

Fixes: 100e25738659 ("usb: typec: Add driver for Thunderbolt 3 Alternate Mode")
Signed-off-by: Benson Leung <bleung@chromium.org>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/Z5PstnlA52Z1F2SU@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: thunderbolt: Fix loops that iterate TYPEC_PLUG_SOP_P and TYPEC_PLUG_SOP_PP 2025-02-03T15:30:37+00:00 Benson Leung bleung@chromium.org 2025-01-24T19:40:23+00:00 b51c1e8d2f49342b2087338c72511326fdb7b172 Fixes these Smatch static checker warnings: drivers/usb/typec/altmodes/thunderbolt.c:116 tbt_altmode_work() warn: why is zero skipped 'i' drivers/usb/typec/altmodes/thunderbolt.c:147 tbt_enter_modes_ordered() warn: why is zero skipped 'i' drivers/usb/typec/altmodes/thunderbolt.c:328 tbt_altmode_remove() warn: why is zero skipped 'i' Fixes: 100e25738659 ("usb: typec: Add driver for Thunderbolt 3 Alternate Mode") Signed-off-by: Benson Leung <bleung@chromium.org> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/Z5Psp615abaaId6J@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Fixes these Smatch static checker warnings:
drivers/usb/typec/altmodes/thunderbolt.c:116 tbt_altmode_work() warn: why is zero skipped 'i'
drivers/usb/typec/altmodes/thunderbolt.c:147 tbt_enter_modes_ordered() warn: why is zero skipped 'i'
drivers/usb/typec/altmodes/thunderbolt.c:328 tbt_altmode_remove() warn: why is zero skipped 'i'

Fixes: 100e25738659 ("usb: typec: Add driver for Thunderbolt 3 Alternate Mode")
Signed-off-by: Benson Leung <bleung@chromium.org>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/Z5Psp615abaaId6J@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: Print err when displayport fails to enter 2024-12-24T07:56:05+00:00 Abhishek Pandit-Subedi abhishekpandit@chromium.org 2024-12-13T23:35:45+00:00 5399a1bac6a8f67eb180ac900641c1836cc3c0dd Print the error reason for typec_altmode_enter so users can understand why displayport failed to enter. Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Benson Leung <bleung@chromium.org> Link: https://lore.kernel.org/r/20241213153543.v5.4.I6cff9d767b0f8ab6458d8940941e42c920902d49@changeid Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Print the error reason for typec_altmode_enter so users can understand
why displayport failed to enter.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Benson Leung <bleung@chromium.org>
Link: https://lore.kernel.org/r/20241213153543.v5.4.I6cff9d767b0f8ab6458d8940941e42c920902d49@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: Add driver for Thunderbolt 3 Alternate Mode 2024-12-24T07:56:05+00:00 Heikki Krogerus heikki.krogerus@linux.intel.com 2024-12-13T23:35:43+00:00 100e257386595b3f1865ca8a991e2ba74f9701ff Thunderbolt 3 Alternate Mode entry flow is described in USB Type-C Specification Release 2.0. Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Co-developed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> Reviewed-by: Benson Leung <bleung@chromium.org> Link: https://lore.kernel.org/r/20241213153543.v5.2.I3080b036e8de0b9957c57c1c3059db7149c5e549@changeid Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Thunderbolt 3 Alternate Mode entry flow is described in
USB Type-C Specification Release 2.0.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Co-developed-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Benson Leung <bleung@chromium.org>
Link: https://lore.kernel.org/r/20241213153543.v5.2.I3080b036e8de0b9957c57c1c3059db7149c5e549@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: Only use SVID for matching altmodes 2024-12-24T07:56:05+00:00 Abhishek Pandit-Subedi abhishekpandit@chromium.org 2024-12-13T23:35:42+00:00 8541bf0239b8509ecc1192b2e26768a36fd9c944 Mode in struct typec_altmode is used to indicate the index of the altmode on a port, partner or plug. It is used in enter mode VDMs but doesn't make much sense for matching against altmode drivers or for matching partner to port altmodes. Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Benson Leung <bleung@chromium.org> Link: https://lore.kernel.org/r/20241213153543.v5.1.Ie0d37646f18461234777d88b4c3e21faed92ed4f@changeid Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Mode in struct typec_altmode is used to indicate the index of the
altmode on a port, partner or plug. It is used in enter mode VDMs but
doesn't make much sense for matching against altmode drivers or for
matching partner to port altmodes.

Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Benson Leung <bleung@chromium.org>
Link: https://lore.kernel.org/r/20241213153543.v5.1.Ie0d37646f18461234777d88b4c3e21faed92ed4f@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: Fix typo in comment 2024-10-04T13:08:45+00:00 Yu Jiaoliang yujiaoliang@vivo.com 2024-09-19T01:46:26+00:00 c837ce6020efaa70ff823129444fc3cb77bce9b6 Fix typos: reseet->reset, reaach->reach, compatiple->compatible. Signed-off-by: Yu Jiaoliang <yujiaoliang@vivo.com> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Link: https://lore.kernel.org/r/20240919014646.1635774-1-yujiaoliang@vivo.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Fix typos:
reseet->reset,
reaach->reach,
compatiple->compatible.

Signed-off-by: Yu Jiaoliang <yujiaoliang@vivo.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20240919014646.1635774-1-yujiaoliang@vivo.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: typec: Update sysfs when setting ops 2024-06-04T13:44:27+00:00 Abhishek Pandit-Subedi abhishekpandit@chromium.org 2024-05-10T20:12:42+00:00 fe8db0bbe04d31ab17dc60e205c4a3365c92e67c When adding altmode ops, update the sysfs group so that visibility is also recalculated. Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Reviewed-by: Benson Leung <bleung@chromium.org> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> Signed-off-by: Jameson Thies <jthies@google.com> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Link: https://lore.kernel.org/r/20240510201244.2968152-3-jthies@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
When adding altmode ops, update the sysfs group so that visibility is
also recalculated.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Benson Leung <bleung@chromium.org>
Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Signed-off-by: Jameson Thies <jthies@google.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20240510201244.2968152-3-jthies@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>