[PATCH] drm/stm: ltdc: update planes at next vblank to avoid partial refresh

[Yannick Fertré]

Plane updates must be synchronized on vblank with the shadow register mechanism
to avoid partial refresh on screen.

Signed-off-by: Yannick Fertré <yannick.fertre at st.com>
---
 drivers/gpu/drm/stm/ltdc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index b1741a9..c2d0800 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -426,8 +426,8 @@ static void ltdc_crtc_atomic_enable(struct drm_crtc *crtc,
 	/* Enable IRQ */
 	reg_set(ldev->regs, LTDC_IER, IER_RRIE | IER_FUIE | IER_TERRIE);
 
-	/* Immediately commit the planes */
-	reg_set(ldev->regs, LTDC_SRCR, SRCR_IMR);
+	/* Commit shadow registers = update planes at next vblank */
+	reg_set(ldev->regs, LTDC_SRCR, SRCR_VBR);
 
 	/* Enable LTDC */
 	reg_set(ldev->regs, LTDC_GCR, GCR_LTDCEN);
-- 
2.7.4