On Fri, Jan 31, 2025 at 02:49:59PM +0200, Jani Nikula wrote:
> Instead of iterating the valid BPP array directly, switch to the same
> approach as xelpd_dsc_compute_link_config(), with a separate function to
> check if the DSC BPP is valid. This prepares us for unifying the
> platform specific functions.
>
> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Reviewed-by: Imre Deak <imre.deak@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_dp.c | 33 +++++++++++++++++++------
> 1 file changed, 26 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index 4e7b3dd4067c..ac67f2d2f86a 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2069,6 +2069,26 @@ static int intel_dp_dsc_bpp_step_x16(const struct intel_connector *connector)
> return 16 / incr;
> }
>
> +/* Note: This is not universally usable! */
> +static bool intel_dp_dsc_valid_bpp(struct intel_dp *intel_dp, int bpp_x16)
> +{
> + struct intel_display *display = to_intel_display(intel_dp);
> + int i;
> +
> + if (DISPLAY_VER(display) >= 13)
> + return true;
> +
> + if (fxp_q4_to_frac(bpp_x16))
> + return false;
> +
> + for (i = 0; i < ARRAY_SIZE(valid_dsc_bpp); i++) {
> + if (fxp_q4_to_int(bpp_x16) == valid_dsc_bpp[i])
> + return true;
> + }
> +
> + return false;
> +}
> +
> /*
> * From a list of valid compressed bpps try different compressed bpp and find a
> * suitable link configuration that can support it.
> @@ -2082,21 +2102,20 @@ icl_dsc_compute_link_config(struct intel_dp *intel_dp,
> int bpp_step_x16,
> int timeslots)
> {
> - int i, ret;
> + int bpp_x16;
> + int ret;
>
> - for (i = ARRAY_SIZE(valid_dsc_bpp) - 1; i >= 0; i--) {
> - if (valid_dsc_bpp[i] < fxp_q4_to_int(min_bpp_x16) ||
> - valid_dsc_bpp[i] > fxp_q4_to_int(max_bpp_x16))
> + for (bpp_x16 = max_bpp_x16; bpp_x16 >= min_bpp_x16; bpp_x16 -= bpp_step_x16) {
> + if (!intel_dp_dsc_valid_bpp(intel_dp, bpp_x16))
> continue;
>
> ret = dsc_compute_link_config(intel_dp,
> pipe_config,
> limits,
> - valid_dsc_bpp[i] << 4,
> + bpp_x16,
> timeslots);
> if (ret == 0) {
> - pipe_config->dsc.compressed_bpp_x16 =
> - fxp_q4_from_int(valid_dsc_bpp[i]);
> + pipe_config->dsc.compressed_bpp_x16 = bpp_x16;
> return 0;
> }
> }
> --
> 2.39.5
>
