On Wed, Feb 08, 2023 at 08:53:19PM +0000, Prashant Malani wrote:
> 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>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
>
> I realize this is a bit late in the release cycle, but figured since it
> is a fix it might still be considered. Please let me know if it's too
> late and I can re-send this after the 6.3-rc1 is released. Thanks!
>
> drivers/usb/typec/altmodes/displayport.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
> index 20db51471c98..662cd043b50e 100644
> --- a/drivers/usb/typec/altmodes/displayport.c
> +++ b/drivers/usb/typec/altmodes/displayport.c
> @@ -547,10 +547,10 @@ int dp_altmode_probe(struct typec_altmode *alt)
> /* 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);
> --
> 2.39.1.519.gcb327c4b5f-goog
thanks,
--
heikki
