[PATCH] drm/atomic-helper: implementatations for legacy interfaces

[Daniel Vetter]

On Wed, Nov 05, 2014 at 02:48:48PM -0500, Sean Paul wrote:
> > + if (!crtc && crtc != set->crtc)
> 
> I think this should be an ||

Hm. My idea idea was actually something along the lines of
diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
index 4f80885de3f6..077c792c46e0 100644
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@@ -1271,7 +1271,14 @@ static int update_output_state(struct drm_atomic_state *state,
 		struct drm_crtc *crtc = state->crtcs[i];
 		struct drm_crtc_state *crtc_state = state->crtc_states[i];
 
-		if (!crtc && crtc != set->crtc)
+		if (!crtc)
+			continue;
+
+		/* Don't update ->enable for the CRTC in the set_config request,
+		 * since a mismatch would indicate a bug in the upper layers.
+		 * The actual modeset code later on will catch any
+		 * inconsistencies here. */
+		if (crtc == set->crtc)
 			continue;
 
 		crtc_state->enable =


I.e. that we don't recompute the new enable state for set->crtc so that we
can catch bug in the helper function or core drm code which maps the
legacy ->set_config to the atomic interface.

Still r-b with that change applied, or want to take a deeper look again?
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch