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The drm_bridge_funcs atomic_get_output_bus_fmts operation should be the same for likely every HDMI connector bridge, unless such an HDMI connector bridge has some special hardware restrictions that I cannot envision yet. To avoid code duplication and standardize on a set of media bus formats that the HDMI output color formats translate to, add a common helper function that implements this operation to the drm bridge helpers. The function returns a list of output bus formats based on the HDMI bridge's current output bits-per-component, and its bitmask of supported color formats. To guard against future expansion of DRM_OUTPUT_COLOR_FORMAT outgrowing the hweight8 call, add a BUILD_BUG_ON statement where it's used that checks for DRM_OUTPUT_COLOR_FORMAT_COUNT. The justification for not using hweight32 in all cases is that not all ISAs have a popcount instruction, and will benefit from a smaller/faster software implementation that doesn't have to operate across all bits. The justification for not defining an hweight_color depending on the value of DRM_OUTPUT_COLOR_FORMAT_COUNT is that this count enum value is only known at compile time, not at preprocessor time. Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com> Reviewed-by: Daniel Stone <daniel@fooishbar.org> Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com> Link: https://patch.msgid.link/20260609-color-format-v17-7-35739b5782cc@collabora.com Signed-off-by: Daniel Stone <daniels@collabora.com>