Re: [PATCH] usb: typec: ucsi: Invert DisplayPort role assignment
From: Heikki Krogerus
Date: Fri Jun 05 2026 - 09:06:16 EST
On Mon, Jun 01, 2026 at 02:28:37PM +0000, Andrei Kuchynski wrote:
> The existing implementation assigned these flags backwards, configuring
> the partner's DisplayPort role to match the port's role instead of
> complementing it.
> This prevents proper configuration during DP altmode activation, often
> causing `pin_assignment` to remain 0 in `dp_altmode_configure()` and
> resulting in VDM negotiation failures:
>
> [ 583.328246] typec port1.1: VDM 0xff01a150 failed
>
> Additionally, the fix ensures that the `pin_assignment` sysfs attribute
> displays the correct values.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: af8622f6a585 ("usb: typec: ucsi: Support for DisplayPort alt mode")
> Signed-off-by: Andrei Kuchynski <akuchynski@xxxxxxxxxxxx>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/typec/ucsi/displayport.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/typec/ucsi/displayport.c b/drivers/usb/typec/ucsi/displayport.c
> index 8aae80b457d74..669f08013c7ab 100644
> --- a/drivers/usb/typec/ucsi/displayport.c
> +++ b/drivers/usb/typec/ucsi/displayport.c
> @@ -166,12 +166,12 @@ static int ucsi_displayport_status_update(struct ucsi_dp *dp)
> * that Multi-function is preferred.
> */
> if (DP_CAP_CAPABILITY(cap) & DP_CAP_UFP_D) {
> - dp->data.status |= DP_STATUS_CON_UFP_D;
> + dp->data.status |= DP_STATUS_CON_DFP_D;
>
> if (DP_CAP_UFP_D_PIN_ASSIGN(cap) & BIT(DP_PIN_ASSIGN_D))
> dp->data.status |= DP_STATUS_PREFER_MULTI_FUNC;
> } else {
> - dp->data.status |= DP_STATUS_CON_DFP_D;
> + dp->data.status |= DP_STATUS_CON_UFP_D;
>
> if (DP_CAP_DFP_D_PIN_ASSIGN(cap) & BIT(DP_PIN_ASSIGN_D))
> dp->data.status |= DP_STATUS_PREFER_MULTI_FUNC;
> --
> 2.54.0.823.g6e5bcc1fc9-goog
--
heikki