diff mbox series

[06/10] Revert "usb: typec: displayport: Receive DP Status Update NAK request exit dp altmode"

Message ID 20250616133147.1835939-7-akuchynski@chromium.org
State New
Headers show
Series USB Type-C mode selection | expand

Commit Message

Andrei Kuchynski June 16, 2025, 1:31 p.m. UTC 
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@chromium.org>
---
 drivers/usb/typec/altmodes/displayport.c | 4 ----
 1 file changed, 4 deletions(-)
diff mbox series

Patch

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);