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| author | Srinivasan Shanmugam <srinivasan.shanmugam@amd.com> | 2026-03-15 16:00:26 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-03-25 13:10:45 +0300 |
| commit | 430334e9e4e815b0541f8337c2dbd49d7d3b55fa (patch) | |
| tree | 8b08f55f71c9ef4eee9f0f2fca7b3ac314fb2bc2 /drivers/gpu | |
| parent | 58abeb7b9562f25bdfa2f5ae5ce803eb02e74433 (diff) | |
| download | linux-430334e9e4e815b0541f8337c2dbd49d7d3b55fa.tar.xz | |
drm/amd/display: Fix DisplayID not-found handling in parse_edid_displayid_vrr()
[ Upstream commit 2323b019651ad81c20a0f7f817c63392b3110652 ]
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>
(cherry picked from commit 91c7e6342e98c846b259c57273436fdea4c043f2)
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/gpu')
| -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 7db2d1a3784b..77840b6cb206 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -12864,7 +12864,7 @@ 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 */ @@ -12874,7 +12874,7 @@ static void parse_edid_displayid_vrr(struct drm_connector *connector, break; } - if (edid_ext == NULL) + if (i == edid->extensions) return; while (j < EDID_LENGTH) { |