From: Alex Hung <alex.hung@amd.com>
Date: Wed, 4 Jun 2025 00:30:55 +0000 (-0600)
Subject: drm/amd/display: Check dce_hwseq before dereferencing it
X-Git-Tag: v6.6.122~211
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=60e450eec5d63113c6ad5c456ce64c12b4496a6e;p=thirdparty%2Fkernel%2Fstable.git

drm/amd/display: Check dce_hwseq before dereferencing it

commit b669507b637eb6b1aaecf347f193efccc65d756e upstream.

[WHAT]

hws was checked for null earlier in dce110_blank_stream, indicating hws
can be null, and should be checked whenever it is used.

Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 79db43611ff61280b6de58ce1305e0b2ecf675ad)
Cc: stable@vger.kernel.org
Signed-off-by: Rahul Sharma <black.hawk@163.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

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 0172fede51b5b..14f5b4f00f724 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
@@ -1228,7 +1228,7 @@ void dce110_blank_stream(struct pipe_ctx *pipe_ctx)
 	struct dce_hwseq *hws = link->dc->hwseq;
 
 	if (link->local_sink && link->local_sink->sink_signal == SIGNAL_TYPE_EDP) {
-		if (!link->skip_implict_edp_power_control)
+		if (!link->skip_implict_edp_power_control && hws)
 			hws->funcs.edp_backlight_control(link, false);
 		link->dc->hwss.set_abm_immediate_disable(pipe_ctx);
 	}