drm/amd/display: ensure dentist display clock update finished in DCN20

[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@amd.com>
Acked-by: Solomon Chiu <solomon.chiu@amd.com>
Signed-off-by: Dale Zhao <dale.zhao@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
This commit is contained in:
Dale Zhao 2021-07-16 09:38:17 +08:00 committed by Alex Deucher
parent 8d177577cd
commit b53e041d8e

View File

@ -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);