[PATCH 06/10] Revert "usb: typec: displayport: Receive DP Status Update NAK request exit dp altmode"
From: Andrei Kuchynski
Date: Mon Jun 16 2025 - 09:38:07 EST
This reverts commit b4b38ffb38c91afd4dc387608db26f6fc34ed40b.
The commit introduced a deadlock with the cros_ec_typec driver.
The deadlock occurs due to a recursive lock acquisition of
`cros_typec_altmode_work::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
This revert is considered safe as no other known driver sends back
DP_CMD_STATUS_UPDATE command with the NAK flag.
Signed-off-by: Andrei Kuchynski <akuchynski@xxxxxxxxxxxx>
---
drivers/usb/typec/altmodes/displayport.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
index b09b58d7311d..ac84a6d64c2f 100644
--- a/drivers/usb/typec/altmodes/displayport.c
+++ b/drivers/usb/typec/altmodes/displayport.c
@@ -393,10 +393,6 @@ static int dp_altmode_vdm(struct typec_altmode *alt,
break;
case CMDT_RSP_NAK:
switch (cmd) {
- case DP_CMD_STATUS_UPDATE:
- if (typec_altmode_exit(alt))
- dev_err(&dp->alt->dev, "Exit Mode Failed!\n");
- break;
case DP_CMD_CONFIGURE:
dp->data.conf = 0;
ret = dp_altmode_configured(dp);
--
2.50.0.rc1.591.g9c95f17f64-goog