This is a note to let you know that I've just added the patch titled
usb: typec: altmodes/displayport: Fix probe pin assign check
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-typec-altmodes-displayport-fix-probe-pin-assign-check.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 54e5c00a4eb0a4c663445b245f641bbfab142430 Mon Sep 17 00:00:00 2001
From: Prashant Malani <pmalani@xxxxxxxxxxxx>
Date: Wed, 8 Feb 2023 20:53:19 +0000
Subject: usb: typec: altmodes/displayport: Fix probe pin assign check
From: Prashant Malani <pmalani@xxxxxxxxxxxx>
commit 54e5c00a4eb0a4c663445b245f641bbfab142430 upstream.
While checking Pin Assignments of the port and partner during probe, we
don't take into account whether the peripheral is a plug or receptacle.
This manifests itself in a mode entry failure on certain docks and
dongles with captive cables. For instance, the Startech.com Type-C to DP
dongle (Model #CDP2DP) advertises its DP VDO as 0x405. This would fail
the Pin Assignment compatibility check, despite it supporting
Pin Assignment C as a UFP.
Update the check to use the correct DP Pin Assign macros that
take the peripheral's receptacle bit into account.
Fixes: c1e5c2f0cb8a ("usb: typec: altmodes/displayport: correct pin assignment for UFP receptacles")
Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Diana Zigterman <dzigterman@xxxxxxxxxxxx>
Signed-off-by: Prashant Malani <pmalani@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20230208205318.131385-1-pmalani@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/typec/altmodes/displayport.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/usb/typec/altmodes/displayport.c
+++ b/drivers/usb/typec/altmodes/displayport.c
@@ -526,10 +526,10 @@ static int dp_altmode_probe(struct typec
/* FIXME: Port can only be DFP_U. */
/* Make sure we have compatiple pin configurations */
- if (!(DP_CAP_DFP_D_PIN_ASSIGN(port->vdo) &
- DP_CAP_UFP_D_PIN_ASSIGN(alt->vdo)) &&
- !(DP_CAP_UFP_D_PIN_ASSIGN(port->vdo) &
- DP_CAP_DFP_D_PIN_ASSIGN(alt->vdo)))
+ if (!(DP_CAP_PIN_ASSIGN_DFP_D(port->vdo) &
+ DP_CAP_PIN_ASSIGN_UFP_D(alt->vdo)) &&
+ !(DP_CAP_PIN_ASSIGN_UFP_D(port->vdo) &
+ DP_CAP_PIN_ASSIGN_DFP_D(alt->vdo)))
return -ENODEV;
ret = sysfs_create_group(&alt->dev.kobj, &dp_altmode_group);
Patches currently in stable-queue which might be from pmalani@xxxxxxxxxxxx are
queue-4.19/usb-typec-altmodes-displayport-fix-probe-pin-assign-check.patch
