[PATCH 06/14] drm/amd/display: Fix warning observed in mode change on Vega

[sunpeng.li at amd.com]

From: "Jerry (Fangzhi) Zuo" <Jerry.Zuo at amd.com>

[Why]
DOUBLE_BUFFER_EN bit is getting cleared before enable blanking.
That leads to CRTC_BLANK_DATA_EN is getting updated immediately.

[How]
Get DOUBLE_BUFFER_EN bit set, the same as DCE110.

Change-Id: Ib88dc8b81b4e5dadca1fa086d2b509e491846396
Signed-off-by: Jerry (Fangzhi) Zuo <Jerry.Zuo at amd.com>
Reviewed-by: Charlene Liu <Charlene.Liu at amd.com>
Acked-by: Leo Li <sunpeng.li at amd.com>
---
 drivers/gpu/drm/amd/display/dc/dce120/dce120_timing_generator.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dce120/dce120_timing_generator.c b/drivers/gpu/drm/amd/display/dc/dce120/dce120_timing_generator.c
index 2ea490f..04b866f 100644
--- a/drivers/gpu/drm/amd/display/dc/dce120/dce120_timing_generator.c
+++ b/drivers/gpu/drm/amd/display/dc/dce120/dce120_timing_generator.c
@@ -772,7 +772,7 @@ void dce120_tg_set_blank(struct timing_generator *tg,
 
 	CRTC_REG_SET(
 		CRTC0_CRTC_DOUBLE_BUFFER_CONTROL,
-		CRTC_BLANK_DATA_DOUBLE_BUFFER_EN, 0);
+		CRTC_BLANK_DATA_DOUBLE_BUFFER_EN, 1);
 
 	if (enable_blanking)
 		CRTC_REG_SET(CRTC0_CRTC_BLANK_CONTROL, CRTC_BLANK_DATA_EN, 1);
-- 
2.7.4