[PATCHv2 3/4] drm: make drm_atomic_set_mode_prop_for_crtc() more reliable

[Tomi Valkeinen]

drm_atomic_set_mode_prop_for_crtc() does not clear the state->mode, so
old data may be left there when a new mode is set, possibly causing odd
issues.

This patch improves the situation by always clearing the state->mode
first.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen at ti.com>
Cc: stable at vger.kernel.org
---
 drivers/gpu/drm/drm_atomic.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index 3ff1ed7b33db..c204ef32df16 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -351,6 +351,8 @@ int drm_atomic_set_mode_prop_for_crtc(struct drm_crtc_state *state,
 	drm_property_unreference_blob(state->mode_blob);
 	state->mode_blob = NULL;
 
+	memset(&state->mode, 0, sizeof(state->mode));
+
 	if (blob) {
 		if (blob->length != sizeof(struct drm_mode_modeinfo) ||
 		    drm_mode_convert_umode(&state->mode,
@@ -363,7 +365,6 @@ int drm_atomic_set_mode_prop_for_crtc(struct drm_crtc_state *state,
 		DRM_DEBUG_ATOMIC("Set [MODE:%s] for CRTC state %p\n",
 				 state->mode.name, state);
 	} else {
-		memset(&state->mode, 0, sizeof(state->mode));
 		state->enable = false;
 		DRM_DEBUG_ATOMIC("Set [NOMODE] for CRTC state %p\n",
 				 state);
-- 
2.5.0