From: SivapiriyanKumarasamy sivapiriyan.kumarasamy@amd.com

[ Upstream commit c7990daebe71d11a9e360b5c3b0ecd1846a3a4bb ]

[WHY] Currently we don't wait for blacklight programming completion in DMCU when setting backlight level. Some sequences such as PSR static screen event trigger reprogramming requires it to be complete.

[How] Add generic wait for dmcu command completion in set backlight level.

Signed-off-by: SivapiriyanKumarasamy sivapiriyan.kumarasamy@amd.com Reviewed-by: Anthony Koo Anthony.Koo@amd.com Acked-by: Leo Li sunpeng.li@amd.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/amd/display/dc/dce/dce_abm.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c b/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c index 070ab56a8aca7..da8b198538e5f 100644 --- a/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c @@ -242,6 +242,10 @@ static void dmcu_set_backlight_level( s2 |= (level << ATOM_S2_CURRENT_BL_LEVEL_SHIFT);

REG_WRITE(BIOS_SCRATCH_2, s2); + + /* waitDMCUReadyForCmd */ + REG_WAIT(MASTER_COMM_CNTL_REG, MASTER_COMM_INTERRUPT, + 0, 1, 80000); }

static void dce_abm_init(struct abm *abm)