linux-kernel - [PATCH AUTOSEL 6.1 20/28] drm/amd/display: Don't check registers, if using AUX BL control

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Message-Id: <20230924131745.1275960-20-sashal@kernel.org>
Date:   Sun, 24 Sep 2023 09:17:37 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Swapnil Patel <swapnil.patel@....com>,
        Wenjing Liu <wenjing.liu@....com>,
        Stylon Wang <stylon.wang@....com>,
        Daniel Wheeler <daniel.wheeler@....com>,
        Alex Deucher <alexander.deucher@....com>,
        Sasha Levin <sashal@...nel.org>, harry.wentland@....com,
        sunpeng.li@....com, Rodrigo.Siqueira@....com,
        christian.koenig@....com, Xinhui.Pan@....com, airlied@...il.com,
        daniel@...ll.ch, Jun.Lei@....com, charlene.liu@....com,
        tony.tascioglu@....com, sancchen@....com, aric.cyr@....com,
        syed.hassan@....com, Jingwen.Zhu@....com, ahmed.ahmed@....com,
        amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org
Subject: [PATCH AUTOSEL 6.1 20/28] drm/amd/display: Don't check registers, if using AUX BL control

From: Swapnil Patel <swapnil.patel@....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@....com>
Acked-by: Stylon Wang <stylon.wang@....com>
Signed-off-by: Swapnil Patel <swapnil.patel@....com>
Tested-by: Daniel Wheeler <daniel.wheeler@....com>
Signed-off-by: Alex Deucher <alexander.deucher@....com>
Signed-off-by: Sasha Levin <sashal@...nel.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 9378c98d02cfe..508f5fe268484 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
@@ -973,7 +973,9 @@ 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