[PATCH 12/14] drm/amd/display: ensure dentist display clock update finished in DCN20

[Solomon Chiu]

From: Dale Zhao <dale.zhao at amd.com>

[Why]
We don't check DENTIST_DISPCLK_CHG_DONE to ensure dentist
display clockis updated to target value. In some scenarios with large
display clock margin, it will deliver unfinished display clock and cause
issues like display black screen.

[How]
Checking DENTIST_DISPCLK_CHG_DONE to ensure display clock
has been update to target value before driver do other clock related
actions.

Reviewed-by: Cyr Aric <aric.cyr at amd.com>
Acked-by: Solomon Chiu <solomon.chiu at amd.com>
Signed-off-by: Dale Zhao <dale.zhao at amd.com>
---
 drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c
index eee406d11b1e..0d01aa9f15a6 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn20/dcn20_clk_mgr.c
@@ -197,7 +197,7 @@ void dcn20_update_clocks_update_dentist(struct clk_mgr_internal *clk_mgr, struct
 
 	REG_UPDATE(DENTIST_DISPCLK_CNTL,
 			DENTIST_DISPCLK_WDIVIDER, dispclk_wdivider);
-//	REG_WAIT(DENTIST_DISPCLK_CNTL, DENTIST_DISPCLK_CHG_DONE, 1, 5, 100);
+	REG_WAIT(DENTIST_DISPCLK_CNTL, DENTIST_DISPCLK_CHG_DONE, 1, 50, 1000);
 	REG_UPDATE(DENTIST_DISPCLK_CNTL,
 			DENTIST_DPPCLK_WDIVIDER, dppclk_wdivider);
 	REG_WAIT(DENTIST_DISPCLK_CNTL, DENTIST_DPPCLK_CHG_DONE, 1, 5, 100);
-- 
2.25.1