On Thu, Jan 16, 2025 at 03:24:16PM +0530, Ankit Nautiyal wrote:
> While setting the bounds for compressed bpp we ensure that the
> compressed bpp is less than the pipe bpp.
>
> This gives an issue with 420 output format where effective link bpp is
> half that of the pipe bpp. Therefore instead of pipe bpp use link bpp to
> set the bounds for the compressed bpp.
>
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_dp.c | 10 ++++++++--
patches to i915, even when they target only platforms supported by
xe should also be sent to intel-gfx mainlinlist...
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 1ad25c37f3c2..47fcfbcb893b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2068,9 +2068,12 @@ icl_dsc_compute_link_config(struct intel_dp *intel_dp,
> int timeslots)
> {
> int i, ret;
> + int link_bpp;
> +
> + link_bpp = intel_dp_output_bpp(pipe_config->output_format, pipe_bpp);
>
> /* Compressed BPP should be less than the Input DSC bpp */
> - dsc_max_bpp = min(dsc_max_bpp, pipe_bpp - 1);
> + dsc_max_bpp = min(dsc_max_bpp, link_bpp - 1);
>
> for (i = 0; i < ARRAY_SIZE(valid_dsc_bpp); i++) {
> if (valid_dsc_bpp[i] < dsc_min_bpp)
> @@ -2113,6 +2116,7 @@ xelpd_dsc_compute_link_config(struct intel_dp *intel_dp,
> u8 bppx16_incr = drm_dp_dsc_sink_bpp_incr(connector->dp.dsc_dpcd);
> u16 compressed_bppx16;
> u8 bppx16_step;
> + int link_bpp;
> int ret;
>
> if (DISPLAY_VER(display) < 14 || bppx16_incr <= 1)
> @@ -2120,8 +2124,10 @@ xelpd_dsc_compute_link_config(struct intel_dp *intel_dp,
> else
> bppx16_step = 16 / bppx16_incr;
>
> + link_bpp = intel_dp_output_bpp(pipe_config->output_format, pipe_bpp);
> +
> /* Compressed BPP should be less than the Input DSC bpp */
> - dsc_max_bpp = min(dsc_max_bpp << 4, (pipe_bpp << 4) - bppx16_step);
> + dsc_max_bpp = min(dsc_max_bpp << 4, (link_bpp << 4) - bppx16_step);
> dsc_min_bpp = dsc_min_bpp << 4;
>
> for (compressed_bppx16 = dsc_max_bpp;
> --
> 2.45.2
>
