[PATCH 5.3 038/112] usb: typec: ucsi: displayport: Fix for the mode entering routine

[Greg Kroah-Hartman]

From: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>

commit f2372b87c386871b16d7dbda680d98d4092ab708 upstream.

Making sure that ucsi_displayport_enter() function does not
return an error if the displayport alternate mode has
already been entered. It's normal that the firmware (or
controller) has already entered the alternate mode by the
time the operating system is notified about the device.

Fixes: af8622f6a585 ("usb: typec: ucsi: Support for DisplayPort alt mode")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20191004100219.71152-3-heikki.krogerus@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/usb/typec/ucsi/displayport.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/usb/typec/ucsi/displayport.c
+++ b/drivers/usb/typec/ucsi/displayport.c
@@ -75,6 +75,8 @@ static int ucsi_displayport_enter(struct
 
 	if (cur != 0xff) {
 		mutex_unlock(&dp->con->lock);
+		if (dp->con->port_altmode[cur] == alt)
+			return 0;
 		return -EBUSY;
 	}