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| author | Harry Wentland <harry.wentland@amd.com> | 2026-08-04 17:04:04 -0400 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2026-08-19 10:14:28 -0400 |
| commit | 4f40873f8a4107df2b9c8e68c947c4fd0cd519d2 (patch) | |
| tree | 7004b6d0beb2547a20ec19948c25c0fe9a464118 /drivers/gpu/drm/amd/display | |
| parent | 0e4ef0ead600e367b4dd431daa97a345a5ff8a86 (diff) | |
| download | linux-4f40873f8a4107df2b9c8e68c947c4fd0cd519d2.tar.gz linux-4f40873f8a4107df2b9c8e68c947c4fd0cd519d2.zip | |
drm/amd/display: avoid divide-by-zero in __is_lut_linear()
__is_lut_linear() computes the expected value of each entry with
expected = i * MAX_DRM_LUT_VALUE / (size - 1);
If it is ever called with a single-entry LUT, size - 1 is zero and the
kernel takes a divide error (#DE). A LUT with fewer than two entries
cannot describe a linear mapping anyway, so return false early instead
of dividing by zero.
Fixes: 086247a4b2fb ("drm/amd/display: Use 4096 lut entries")
Cc: stable@vger.kernel.org
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Melissa Wen <mwen@igalia.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Diffstat (limited to 'drivers/gpu/drm/amd/display')
| -rw-r--r-- | drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c index 7b68c6846039..26e5c89375a5 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_color.c @@ -471,6 +471,12 @@ bool __is_lut_linear(const struct drm_color_lut *lut, uint32_t size) uint32_t expected; int delta; + /* A LUT with fewer than two entries can't be interpolated and would + * divide by zero below (size - 1); it can't be treated as linear. + */ + if (size < 2) + return false; + for (i = 0; i < size; i++) { /* All color values should equal */ if ((lut[i].red != lut[i].green) || (lut[i].green != lut[i].blue)) |