From 5a9b2ea83b97a3ff6453b4a928b366f6e5f74c07 Mon Sep 17 00:00:00 2001
From: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Date: Thu, 2 Apr 2020 15:59:44 -0400
Subject: drm/amd/display: Avoid NULL pointer in set_backlight when ABM is NULL
Git-commit: f1029e7ead9a5f13ef040dfbe1473b975f927b41
Patch-mainline: v5.8-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
[Why]
On ASIC without ABM support (most dGPU) we run into a null pointer
dereference when attempting to set the backlight level.
[How]
This function requires ABM, so fix up the condition to only allow
DMCU to be optional.
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Reviewed-by: Wyatt Wood <Wyatt.Wood@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/display/dc/core/dc_link.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
index 1c5c11d6347e..a926c1c3f57d 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -2462,8 +2462,7 @@ bool dc_link_set_backlight_level(const struct dc_link *link,
int i;
DC_LOGGER_INIT(link->ctx->logger);
- if ((dmcu == NULL && abm == NULL) ||
- (abm->funcs->set_backlight_level_pwm == NULL))
+ if (abm == NULL || (abm->funcs->set_backlight_level_pwm == NULL))
return false;
if (dmcu)
--
2.28.0