drm/amd/display: fix eDP fast bootup for pre-raven asic

[Why]
For fastboot, Bios will light up eDP before SW driver is loaded. SW
driver will check if eDP is lit by bios through reading the
BIOS_SCRATCH_3 register. If lit, SW driver will not power down eDP
power and phy to save time.

Definition of BIOS_SCRATCH_3 are missing for pre-raven asic. This
causes eDP fast boot to not work property. For some eDP panels, even
if dp tx sends NoVideoStream_flag =1 and dpcd 0x600=2, eDP rx may not
handle properly. This may cause a short flash on screen.

[How] Add definition of BIOS_SCRATCH_3 for all asic

Signed-off-by: hersen wu <hersenxs.wu@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Charlene Liu <Charlene.Liu@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Acked-by: Yongqiang Sun <yongqiang.sun@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/drm/amd/display/dc/dce80/dce80_resource.c b/drivers/gpu/drm/amd/display/dc/dce80/dce80_resource.c
index e0bba0bc996b..2eca81b5cf2f 100644
--- a/drivers/gpu/drm/amd/display/dc/dce80/dce80_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dce80/dce80_resource.c
@@ -77,6 +77,7 @@
 
 #ifndef mmBIOS_SCRATCH_2
 	#define mmBIOS_SCRATCH_2 0x05CB
+	#define mmBIOS_SCRATCH_3 0x05CC
 	#define mmBIOS_SCRATCH_6 0x05CF
 #endif
 
@@ -358,6 +359,7 @@ static const struct dce110_clk_src_mask cs_mask = {
 };
 
 static const struct bios_registers bios_regs = {
+	.BIOS_SCRATCH_3 = mmBIOS_SCRATCH_3,
 	.BIOS_SCRATCH_6 = mmBIOS_SCRATCH_6
 };