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authorJos Wang <joswang@lenovo.com>2025-02-09 15:19:26 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2025-04-11 16:08:32 +0200
commitb4b38ffb38c91afd4dc387608db26f6fc34ed40b (patch)
tree4c49246f48250e5f0d2b59136ee5d5dc8618614a
parentaaa8f2e959341fd4a3ccf111500eb1e6176678e0 (diff)
usb: typec: displayport: Receive DP Status Update NAK request exit dp altmode
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>
-rw-r--r--drivers/usb/typec/altmodes/displayport.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
index ac84a6d64c2f..b09b58d7311d 100644
--- a/drivers/usb/typec/altmodes/displayport.c
+++ b/drivers/usb/typec/altmodes/displayport.c
@@ -393,6 +393,10 @@ 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);