[PATCH 3/7] drm/exynos/mixer: correct vsync configuration sequence

[Andrzej Hajda]

Specification advises to clear vsync indicator before configuring vsync.

Signed-off-by: Andrzej Hajda <a.hajda at samsung.com>
---
 drivers/gpu/drm/exynos/exynos_mixer.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_mixer.c b/drivers/gpu/drm/exynos/exynos_mixer.c
index 52275b4..2df1bb2 100644
--- a/drivers/gpu/drm/exynos/exynos_mixer.c
+++ b/drivers/gpu/drm/exynos/exynos_mixer.c
@@ -900,8 +900,8 @@ static int mixer_enable_vblank(struct exynos_drm_manager *mgr)
 	}
 
 	/* enable vsync interrupt */
-	mixer_reg_writemask(res, MXR_INT_EN, MXR_INT_EN_VSYNC,
-			MXR_INT_EN_VSYNC);
+	mixer_reg_writemask(res, MXR_INT_STATUS, ~0, MXR_INT_CLEAR_VSYNC);
+	mixer_reg_writemask(res, MXR_INT_EN, ~0, MXR_INT_EN_VSYNC);
 
 	return 0;
 }
@@ -912,6 +912,7 @@ static void mixer_disable_vblank(struct exynos_drm_manager *mgr)
 	struct mixer_resources *res = &mixer_ctx->mixer_res;
 
 	/* disable vsync interrupt */
+	mixer_reg_writemask(res, MXR_INT_STATUS, ~0, MXR_INT_CLEAR_VSYNC);
 	mixer_reg_writemask(res, MXR_INT_EN, 0, MXR_INT_EN_VSYNC);
 }
 
@@ -1101,6 +1102,8 @@ static void mixer_poweron(struct exynos_drm_manager *mgr)
 
 	mixer_reg_writemask(res, MXR_STATUS, ~0, MXR_STATUS_SOFT_RESET);
 
+	if (ctx->int_en & MXR_INT_EN_VSYNC)
+		mixer_reg_writemask(res, MXR_INT_STATUS, ~0, MXR_INT_CLEAR_VSYNC);
 	mixer_reg_write(res, MXR_INT_EN, ctx->int_en);
 	mixer_win_reset(ctx);
 
-- 
1.9.1