diff options
| author | Srinivasan Shanmugam <srinivasan.shanmugam@amd.com> | 2026-03-15 16:00:26 +0300 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2026-03-17 17:39:33 +0300 |
| commit | 91c7e6342e98c846b259c57273436fdea4c043f2 (patch) | |
| tree | 52b1daf6c842f51114164b73731a2ab3c575ed7b | |
| parent | 6736c8ff9d63e847a3b694aeaeb78d4e8ad42464 (diff) | |
| download | linux-91c7e6342e98c846b259c57273436fdea4c043f2.tar.xz | |
drm/amd/display: Fix DisplayID not-found handling in parse_edid_displayid_vrr()
parse_edid_displayid_vrr() searches the EDID extension blocks for a
DisplayID extension before parsing the dynamic video timing range.
The code previously checked whether edid_ext was NULL after the search
loop. However, edid_ext is assigned during each iteration of the loop,
so it will never be NULL once the loop has executed. If no DisplayID
extension is found, edid_ext ends up pointing to the last extension
block, and the NULL check does not correctly detect the failure case.
Instead, check whether the loop completed without finding a matching
DisplayID block by testing "i == edid->extensions". This ensures the
function exits early when no DisplayID extension is present and avoids
parsing an unrelated EDID extension block.
Also simplify the EDID validation check using "!edid ||
!edid->extensions".
Fixes the below:
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:13079 parse_edid_displayid_vrr() warn: variable dereferenced before check 'edid_ext' (see line 13075)
Fixes: a638b837d0e6 ("drm/amd/display: Fix refresh rate range for some panel")
Cc: Roman Li <roman.li@amd.com>
Cc: Alex Hung <alex.hung@amd.com>
Cc: Jerry Zuo <jerry.zuo@amd.com>
Cc: Sun peng Li <sunpeng.li@amd.com>
Cc: Tom Chung <chiahsuan.chung@amd.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
| -rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index 3352b1cc7dc8..6fb8c4f447a9 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -13125,7 +13125,7 @@ static void parse_edid_displayid_vrr(struct drm_connector *connector, u16 min_vfreq; u16 max_vfreq; - if (edid == NULL || edid->extensions == 0) + if (!edid || !edid->extensions) return; /* Find DisplayID extension */ @@ -13135,7 +13135,7 @@ static void parse_edid_displayid_vrr(struct drm_connector *connector, break; } - if (edid_ext == NULL) + if (i == edid->extensions) return; while (j < EDID_LENGTH) { |