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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230924131857.1276330-13-sashal@kernel.org>
Date:   Sun, 24 Sep 2023 09:18:50 -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, charlene.liu@....com, Jun.Lei@....com,
        mario.limonciello@....com, tony.tascioglu@....com,
        aric.cyr@....com, Jingwen.Zhu@....com, ahmed.ahmed@....com,
        amd-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org
Subject: [PATCH AUTOSEL 5.15 13/18] 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 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