On Fri, Feb 23, 2018 at 11:26:41AM -0500, Harry Wentland wrote:
On 2018-02-22 04:42 PM, Ville Syrjala wrote:
From: Ville Syrjälä ville.syrjala@linux.intel.com
The documentation for the ctm matrix suggests a two's complement format, but at least the i915 implementation is using sign-magnitude instead. And looks like malidp is doing the same. Change the docs to match the current implementation, and change the type from __s64 to __u64 to drive the point home.
Cc: dri-devel@lists.freedesktop.org Cc: Mihail Atanassov mihail.atanassov@arm.com Cc: Liviu Dudau liviu.dudau@arm.com Cc: Brian Starkey brian.starkey@arm.com Cc: Mali DP Maintainers malidp@foss.arm.com Cc: Johnson Lin johnson.lin@intel.com Cc: Uma Shankar uma.shankar@intel.com Cc: Shashank Sharma shashank.sharma@intel.com Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com
Good clarification. Our new CTM implementation (1) actually assumed two's complement but nobody's using it yet, so we'll patch it to convert.
Another reason to start looking into igt and the tests there? That would have caught this too ... -Daniel
Reviewed-by: Harry Wentland harry.wentland@amd.com
(1) https://patchwork.freedesktop.org/patch/204005/
Harry
include/uapi/drm/drm_mode.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h index 2c575794fb52..b5d7d9e0eff5 100644 --- a/include/uapi/drm/drm_mode.h +++ b/include/uapi/drm/drm_mode.h @@ -598,8 +598,11 @@ struct drm_mode_crtc_lut { };
struct drm_color_ctm {
- /* Conversion matrix in S31.32 format. */
- __s64 matrix[9];
- /*
* Conversion matrix in S31.32 sign-magnitude* (not two's complement!) format.*/- __u64 matrix[9];
};
struct drm_color_lut {
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