From: SivapiriyanKumarasamy <sivapiriyan.kumarasamy@amd.com>
Date: Fri, 14 Jun 2019 19:04:00 +0000 (-0400)
Subject: drm/amd/display: Wait for backlight programming completion in set backlight level
X-Git-Tag: v5.4-rc1~106^2~17^2~281
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=d35d77a6a512f38a89aee9328c67d0c913c7fbea;p=linux.git

drm/amd/display: Wait for backlight programming completion in set backlight level

[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>
---

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 f8903bcabe49..58bd131d5b48 100644
--- a/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c
+++ b/drivers/gpu/drm/amd/display/dc/dce/dce_abm.c
@@ -239,6 +239,10 @@ static void dmcu_set_backlight_level(
 	s2 |= (backlight_8_bit << 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)