Re: [PATCH] drm/gud: don't keep a connector without a CRTC as connector_state

From: Ruben Wauters

Date: Tue Oct 06 2026 - 08:30:28 EST


On Tue, 2026-09-22 at 14:10 +0530, Sajal Gupta wrote:
> If the 'for_each_new_connector_in_state()' loop finishes without
> hitting the break, connector_state is left pointing at the last
> connector visited, which has no CRTC, instead of
> staying NULL.
>
> That skips the "if (!connector_state)" fallback below the loop, which
> looks up the active connector when the state contains none. The
> function then carries on with a connector that is not driven.
>
> Fix by resetting connector_state to NULL for each connector visited that
> has no CRTC, so that it is NULL when none was found and the fallback runs.
>
> Fixes: 40e1a70b4aed ("drm: Add GUD USB Display driver")
> Reported-by: Sashiko <sashiko-bot@xxxxxxxxxx>
> Link: https://sashiko.dev/#/patchset/20260902123254.36987-1-sajal2005gupta@xxxxxxxxx?part=1
> Signed-off-by: Sajal Gupta <sajal2005gupta@xxxxxxxxx>
Acked-by: Ruben Wauters <rubenru09@xxxxxxx>
> ---
> drivers/gpu/drm/gud/gud_pipe.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/gud/gud_pipe.c b/drivers/gpu/drm/gud/gud_pipe.c
> index aa7792966287..5aa5ac2f3727 100644
> --- a/drivers/gpu/drm/gud/gud_pipe.c
> +++ b/drivers/gpu/drm/gud/gud_pipe.c
> @@ -507,6 +507,7 @@ int gud_plane_atomic_check(struct drm_plane *plane,
> for_each_new_connector_in_state(state, connector, connector_state, i) {
> if (connector_state->crtc)
> break;
> + connector_state = NULL;
> }
>
> /*
> --
> 2.55.0

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