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Andres Calderon Jaramillo authored
Prevent the ICL HDR plane pipeline from performing YUV color range correction twice when the input is in limited range. This is done by removing the limited-range code from icl_program_input_csc(). Before this patch the following could happen: user space gives us a YUV buffer in limited range; per the pipeline in [1], the plane would first go through a "YUV Range correct" stage that expands the range; the plane would then go through the "Input CSC" stage which would also expand the range because icl_program_input_csc() would use a matrix and an offset that assume limited-range input; this would ultimately cause dark and light colors to appear darker and lighter than they should respectively. This is an issue because if a buffer switches between being scanned out and being composited with the GPU, the user will see a color difference. If this switching happens quickly and frequently, the user will perceive this as a flickering. [1] https://01.org/sites/default/files/documentation/intel-gfx-prm-osrc-icllp-vol12-displayengine_0.pdf#page=281 Cc: stable@vger.kernel.org Signed-off-by: Andres Calderon Jaramillo <andrescj@chromium.org> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20201215224219.3896256-1-andrescj@google.com
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