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

Plane updates must be synchronized on vblank with the shadow register mechanism to avoid partial refresh on screen. Signed-off-by: Yannick Fertré <[email protected]> Acked-by: Philippe Cornu <[email protected]> Signed-off-by: Benjamin Gaignard <[email protected]> Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
LoveHeat · Apr 24, 2019 · 8ceb856 · 8ceb856
1 parent c64d1cb
commit 8ceb856
Showing 1 changed file with 2 additions and 2 deletions.
diff --git 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);