5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jos Wang joswang@lenovo.com
[ Upstream commit 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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/typec/altmodes/displayport.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c index a2a1baabca933..35d7a4d40d9a4 100644 --- a/drivers/usb/typec/altmodes/displayport.c +++ b/drivers/usb/typec/altmodes/displayport.c @@ -288,6 +288,10 @@ 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);