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

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

[Sajal Gupta]

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@kernel.org>
Link: https://sashiko.dev/#/patchset/20260902123254.36987-1-sajal2005gupta@gmail.com?part=1
Signed-off-by: Sajal Gupta <sajal2005gupta@gmail.com>
---
 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

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

[Ruben Wauters]

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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@kernel.org>
> Link: https://sashiko.dev/#/patchset/20260902123254.36987-1-sajal2005gupta@gmail.com?part=1
> Signed-off-by: Sajal Gupta <sajal2005gupta@gmail.com>
Acked-by: Ruben Wauters <rubenru09@aol.com>
> ---
>  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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