On Tue, Nov 24, 2015 at 10:34:35AM +0100, Maarten Lankhorst wrote:
[...]
> diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> index cee31d43cd1c..fb79c54b2aed 100644
> --- a/drivers/gpu/drm/drm_atomic_helper.c
> +++ b/drivers/gpu/drm/drm_atomic_helper.c
> @@ -420,8 +420,6 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
>  	 * crtc only changed its mode but has the same set of connectors.
>  	 */
>  	for_each_crtc_in_state(state, crtc, crtc_state, i) {
> -		int num_connectors;
> -
>  		/*
>  		 * We must set ->active_changed after walking connectors for
>  		 * otherwise an update that only changes active would result in
> @@ -449,10 +447,7 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
>  		if (ret != 0)
>  			return ret;
>  
> -		num_connectors = drm_atomic_connectors_for_crtc(state,
> -								crtc);
> -
> -		if (crtc_state->enable != !!num_connectors) {
> +		if (crtc_state->enable != !!crtc_state->connector_mask) {

I have difficulty to doubly negate in my head, so something like this
would be a lot clearer in my opinion:

	bool enable = crtc_state->connector_mask != 0;

	...

	if (crtc_state->enable != enable)
		...

Or perhaps even:

	bool disable = crtc_state->connector_mask == 0;

	...

	if (crtc_state->enable == disable)
		...

>  			DRM_DEBUG_ATOMIC("[CRTC:%d] enabled/connectors mismatch\n",
>  					 crtc->base.id);
>  
> @@ -1668,7 +1663,7 @@ static int update_output_state(struct drm_atomic_state *state,
>  		if (crtc == set->crtc)
>  			continue;
>  
> -		if (!drm_atomic_connectors_for_crtc(state, crtc)) {
> +		if (!crtc_state->connector_mask) {

Similarly I think it would be more natural to say:

		if (crtc->state->connector_mask == 0)

here.

Anyway, this is mostly about personal taste, and the change looks
correct to me (after checking twice that I got the double negation
right), so:

Reviewed-by: Thierry Reding <treding@nvidia.com>