diff options
| author | Leo (Sunpeng) Li <sunpeng.li@amd.com> | 2018-02-23 12:59:03 -0500 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2018-03-14 15:08:43 -0500 |
| commit | 5e3e341cee51a755b81a660806bfcad3fdcfc906 (patch) | |
| tree | 739a6c034d7022c0ba23958842579ec04ebbe41d /drivers/gpu/drm/amd/display | |
| parent | a7596f25db13b1f5a2f8a068d8e9a60a23e34451 (diff) | |
drm/amd/display: Convert CTM to 2's complement
DRM's documentation for the color transform matrix does not specify
whether the values are in signed-magnitude, or 2's complement.
Therefore, it was assumed to use 2's complement.
However, existing usermode implementations use signed-magnitude.
Therefore, conform to existing standards, and convert to 2's complement
internally.
Signed-off-by: Leo (Sunpeng) Li <sunpeng.li@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@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 | 15 |
1 files changed, 12 insertions, 3 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 e845c511656e..f6cb502c303f 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 @@ -193,6 +193,7 @@ void amdgpu_dm_set_ctm(struct dm_crtc_state *crtc) struct drm_property_blob *blob = crtc->base.ctm; struct dc_stream_state *stream = crtc->stream; struct drm_color_ctm *ctm; + int64_t val; int i; if (!blob) { @@ -206,7 +207,9 @@ void amdgpu_dm_set_ctm(struct dm_crtc_state *crtc) * DRM gives a 3x3 matrix, but DC wants 3x4. Assuming we're operating * with homogeneous coordinates, augment the matrix with 0's. * - * The format provided is S31.32, which is the same as our fixed31_32. + * The format provided is S31.32, using signed-magnitude representation. + * Our fixed31_32 is also S31.32, but is using 2's complement. We have + * to convert from signed-magnitude to 2's complement. */ for (i = 0; i < 12; i++) { /* Skip 4th element */ @@ -214,8 +217,14 @@ void amdgpu_dm_set_ctm(struct dm_crtc_state *crtc) stream->gamut_remap_matrix.matrix[i] = dal_fixed31_32_zero; continue; } - /* csc[i] = ctm[i - floor(i/4)] */ - stream->gamut_remap_matrix.matrix[i].value = ctm->matrix[i - (i/4)]; + + /* gamut_remap_matrix[i] = ctm[i - floor(i/4)] */ + val = ctm->matrix[i - (i/4)]; + /* If negative, convert to 2's complement. */ + if (val & (1ULL << 63)) + val = -(val & ~(1ULL << 63)); + + stream->gamut_remap_matrix.matrix[i].value = val; } } |