On Thu, Aug 24, 2023 at 11:04:58AM +0300, Imre Deak wrote:
> Computing the non-DSC mode link config is redundant once it's determined
> that DSC will be needed, so skip computing it. In a follow-up patch this
> simplifies setting the link limits which are dependent on the DSC vs.
> non-DSC mode.
>
> While at it sanitize the debug print about the MST DSC fallback path,
> making it similar to the SST DSC one.
>
> Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_dp.c | 22 ++++++++++++------
> drivers/gpu/drm/i915/display/intel_dp_mst.c | 25 +++++++++++++++------
> 2 files changed, 33 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> index cf29562795f75..c580472c06b85 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2246,7 +2246,8 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
> struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
> struct link_config_limits limits;
> bool joiner_needs_dsc = false;
> - int ret;
> + bool dsc_needed;
> + int ret = 0;
>
> intel_dp_compute_config_limits(intel_dp, pipe_config,
> respect_downstream_limits, &limits);
> @@ -2262,13 +2263,20 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
> */
> joiner_needs_dsc = DISPLAY_VER(i915) < 13 && pipe_config->bigjoiner_pipes;
>
> - /*
> - * Optimize for slow and wide for everything, because there are some
> - * eDP 1.3 and 1.4 panels don't work well with fast and narrow.
> - */
> - ret = intel_dp_compute_link_config_wide(intel_dp, pipe_config, conn_state, &limits);
> + dsc_needed = joiner_needs_dsc || intel_dp->force_dsc_en;
> +
> + if (!dsc_needed) {
> + /*
> + * Optimize for slow and wide for everything, because there are some
> + * eDP 1.3 and 1.4 panels don't work well with fast and narrow.
> + */
> + ret = intel_dp_compute_link_config_wide(intel_dp, pipe_config,
> + conn_state, &limits);
> + if (ret)
> + dsc_needed = true;
> + }
>
> - if (ret || joiner_needs_dsc || intel_dp->force_dsc_en) {
> + if (dsc_needed) {
> drm_dbg_kms(&i915->drm, "Try DSC (fallback=%s, joiner=%s, force=%s)\n",
> str_yes_no(ret), str_yes_no(joiner_needs_dsc),
> str_yes_no(intel_dp->force_dsc_en));
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 6c1c996c74e62..c077b999ccb74 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -350,7 +350,8 @@ static int intel_dp_mst_compute_config(struct intel_encoder *encoder,
> const struct drm_display_mode *adjusted_mode =
> &pipe_config->hw.adjusted_mode;
> struct link_config_limits limits;
> - int ret;
> + bool dsc_needed;
> + int ret = 0;
>
> if (adjusted_mode->flags & DRM_MODE_FLAG_DBLSCAN)
> return -EINVAL;
> @@ -365,15 +366,25 @@ static int intel_dp_mst_compute_config(struct intel_encoder *encoder,
>
> intel_dp_mst_compute_config_limits(intel_dp, pipe_config, &limits);
>
> - ret = intel_dp_mst_compute_link_config(encoder, pipe_config,
> - conn_state, &limits);
> + dsc_needed = intel_dp->force_dsc_en;
>
> - if (ret == -EDEADLK)
> - return ret;
> + if (!dsc_needed) {
> + ret = intel_dp_mst_compute_link_config(encoder, pipe_config,
> + conn_state, &limits);
> +
> + if (ret == -EDEADLK)
> + return ret;
> +
> + if (ret)
> + dsc_needed = true;
> + }
>
> /* enable compression if the mode doesn't fit available BW */
> - drm_dbg_kms(&dev_priv->drm, "Force DSC en = %d\n", intel_dp->force_dsc_en);
> - if (ret || intel_dp->force_dsc_en) {
> + if (dsc_needed) {
> + drm_dbg_kms(&dev_priv->drm, "Try DSC (fallback=%s, force=%s)\n",
> + str_yes_no(ret),
> + str_yes_no(intel_dp->force_dsc_en));
> +
> /*
> * FIXME: As bpc is hardcoded to 8, as mentioned above,
> * WARN and ignore the debug flag force_dsc_bpc for now.
> --
> 2.37.2
--
Ville Syrjälä
Intel
