[PATCH AUTOSEL 5.15 13/18] drm/amd/display: Don't check registers, if using AUX BL control

[Sasha Levin]

From: Swapnil Patel <swapnil.patel at amd.com>

[ Upstream commit f5b2c10b57615828b531bb0ae56bd6325a41167e ]

[Why]
Currently the driver looks DCN registers to access if BL is on or not.
This check is not valid if we are using AUX based brightness control.
This causes driver to not send out "backlight off" command during power off
sequence as it already thinks it is off.

[How]
Only check DCN registers if we aren't using AUX based brightness control.

Reviewed-by: Wenjing Liu <wenjing.liu at amd.com>
Acked-by: Stylon Wang <stylon.wang at amd.com>
Signed-off-by: Swapnil Patel <swapnil.patel at amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c b/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c
index 52142d272c868..87825818d43ec 100644
--- a/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c
+++ b/drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c
@@ -980,7 +980,9 @@ void dce110_edp_backlight_control(
 		return;
 	}
 
-	if (link->panel_cntl) {
+	if (link->panel_cntl && !(link->dpcd_sink_ext_caps.bits.oled ||
+		link->dpcd_sink_ext_caps.bits.hdr_aux_backlight_control == 1 ||
+		link->dpcd_sink_ext_caps.bits.sdr_aux_backlight_control == 1)) {
 		bool is_backlight_on = link->panel_cntl->funcs->is_panel_backlight_on(link->panel_cntl);
 
 		if ((enable && is_backlight_on) || (!enable && !is_backlight_on)) {
-- 
2.40.1