[PATCH 07/10] drm/i915/dp: Compute pixel replication count for DSC 12 slices case
Kandpal, Suraj
suraj.kandpal at intel.com
Thu Oct 17 09:44:24 UTC 2024
> -----Original Message-----
> From: Nautiyal, Ankit K <ankit.k.nautiyal at intel.com>
> Sent: Thursday, October 17, 2024 1:54 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: intel-xe at lists.freedesktop.org; Kandpal, Suraj
> <suraj.kandpal at intel.com>
> Subject: [PATCH 07/10] drm/i915/dp: Compute pixel replication count for
> DSC 12 slices case
>
> Add check if pixel replication is required while computing slice count and fill
> the pixel replication count in crtc_state.
> For MST currently 12 slices case is skipped, as it needs the extra pixels for
> bandwidth computation.
>
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_dp.c | 61 ++++++++++++++++++++-
> drivers/gpu/drm/i915/display/intel_dp.h | 1 +
> drivers/gpu/drm/i915/display/intel_dp_mst.c | 20 +++++--
> 3 files changed, 77 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index 6cfc7d1c96ea..ef96b9235636 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -981,13 +981,37 @@ u16
> intel_dp_dsc_get_max_compressed_bpp(struct drm_i915_private *i915,
> return bits_per_pixel;
> }
>
> +static
> +bool can_use_pixel_replication(int mode_hdisplay, u8 slice_count,
> + enum intel_output_format output_format,
> + bool ultrajoiner)
> +{
> + int slice_width;
> +
> + if (!(mode_hdisplay % slice_count))
> + return false;
> +
> + if (!ultrajoiner)
> + return false;
> +
> + slice_width = DIV_ROUND_UP(mode_hdisplay, slice_count);
> +
> + /* Odd slice width is not supported by YCbCr420/422 formats */
> + if (slice_width % 2 && output_format ==
> INTEL_OUTPUT_FORMAT_YCBCR420)
> + return false;
> +
> + return true;
> +}
> +
> u8 intel_dp_dsc_get_slice_count(const struct intel_connector *connector,
> int mode_clock, int mode_hdisplay,
> + enum intel_output_format output_format,
> int num_joined_pipes)
> {
> struct drm_i915_private *i915 = to_i915(connector->base.dev);
> u8 min_slice_count, i;
> int max_slice_width;
> + bool ultrajoiner = num_joined_pipes == 4 ? true : false;
>
> if (mode_clock <= DP_DSC_PEAK_PIXEL_RATE)
> min_slice_count = DIV_ROUND_UP(mode_clock, @@ -1031,7
> +1055,10 @@ u8 intel_dp_dsc_get_slice_count(const struct intel_connector
> *connector,
> if (num_joined_pipes > 1 && valid_dsc_slicecount[i] < 2)
> continue;
>
> - if (mode_hdisplay % test_slice_count)
> + if (mode_hdisplay % test_slice_count &&
> + !can_use_pixel_replication(mode_hdisplay,
> + test_slice_count,
> + output_format, ultrajoiner))
This check here does not make sense this function is already used in conjunction with
mode_hdisplay % test_slice_count which means that we enter can_use_pixel_replication
only if mode_hdisplay % test_slice_count is true and when we go inside can_use_pixel_replication
we have !mode_hdisplay % slice_count now since we have entered this function it means this check will
always evaluate to false. In conclusion, either mode_hdisplay % test_slice_count is not needed or the check inside
can_use_pixel_replication.
Regards,
Suraj Kandpal
> continue;
>
> if (min_slice_count <= test_slice_count) @@ -1458,6 +1485,7
> @@ intel_dp_mode_valid(struct drm_connector *_connector,
> intel_dp_dsc_get_slice_count(connector,
> target_clock,
> mode->hdisplay,
> + output_format,
>
> num_joined_pipes);
> }
>
> @@ -2322,6 +2350,33 @@ static int
> intel_edp_dsc_compute_pipe_bpp(struct intel_dp *intel_dp,
> return 0;
> }
>
> +static
> +int intel_dp_dsc_get_pixel_replication(struct intel_dp *intel_dp,
> + struct intel_crtc_state *pipe_config) {
> + int mode_hdisplay = pipe_config->hw.adjusted_mode.hdisplay;
> + int slice_count = pipe_config->dsc.slice_count;
> + int pixel_replication_count;
> + int slice_width;
> + bool ultrajoiner = false;
> +
> + if (intel_crtc_num_joined_pipes(pipe_config) == 4)
> + ultrajoiner = true;
> +
> + if (!can_use_pixel_replication(mode_hdisplay, slice_count,
> + pipe_config->output_format,
> ultrajoiner))
> + return 0;
> +
> + slice_width = DIV_ROUND_UP(mode_hdisplay, slice_count);
> +
> + pixel_replication_count = (slice_width * slice_count) -
> mode_hdisplay;
> +
> + if (pixel_replication_count >= 0)
> + return pixel_replication_count;
> +
> + return 0;
> +}
> +
> int intel_dp_dsc_compute_config(struct intel_dp *intel_dp,
> struct intel_crtc_state *pipe_config,
> struct drm_connector_state *conn_state,
> @@ -2391,6 +2446,7 @@ int intel_dp_dsc_compute_config(struct intel_dp
> *intel_dp,
> intel_dp_dsc_get_slice_count(connector,
> adjusted_mode-
> >crtc_clock,
> adjusted_mode-
> >crtc_hdisplay,
> + pipe_config-
> >output_format,
> num_joined_pipes);
> if (!dsc_dp_slice_count) {
> drm_dbg_kms(&dev_priv->drm,
> @@ -2400,6 +2456,9 @@ int intel_dp_dsc_compute_config(struct intel_dp
> *intel_dp,
>
> pipe_config->dsc.slice_count = dsc_dp_slice_count;
> }
> +
> + pipe_config->dsc.pixel_replication_count =
> + intel_dp_dsc_get_pixel_replication(intel_dp, pipe_config);
> /*
> * VDSC engine operates at 1 Pixel per clock, so if peak pixel rate
> * is greater than the maximum Cdclock and if slice count is even diff
> --git a/drivers/gpu/drm/i915/display/intel_dp.h
> b/drivers/gpu/drm/i915/display/intel_dp.h
> index 60baf4072dc9..bd7a8232572b 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.h
> +++ b/drivers/gpu/drm/i915/display/intel_dp.h
> @@ -149,6 +149,7 @@ int intel_dp_dsc_sink_max_compressed_bpp(const
> struct intel_connector *connector
> int bpc);
> u8 intel_dp_dsc_get_slice_count(const struct intel_connector *connector,
> int mode_clock, int mode_hdisplay,
> + enum intel_output_format output_format,
> int num_joined_pipes);
> int intel_dp_num_joined_pipes(struct intel_dp *intel_dp,
> struct intel_connector *connector, diff --git
> a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 1a2ff3e1cb68..f1f19e1c4df8 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -154,11 +154,22 @@ static int intel_dp_mst_dsc_get_slice_count(const
> struct intel_connector *connec
> const struct drm_display_mode *adjusted_mode =
> &crtc_state->hw.adjusted_mode;
> int num_joined_pipes = intel_crtc_num_joined_pipes(crtc_state);
> + int slice_count;
>
> - return intel_dp_dsc_get_slice_count(connector,
> - adjusted_mode->clock,
> - adjusted_mode->hdisplay,
> - num_joined_pipes);
> + slice_count = intel_dp_dsc_get_slice_count(connector,
> + adjusted_mode->clock,
> + adjusted_mode->hdisplay,
> + crtc_state->output_format,
> + num_joined_pipes);
> + /*
> + * FIXME: With 12 slice count, extra pixels are added.
> + * Take pixel replication into account for MST BW calculation?
> + * Avoid slice count of 12 for now.
> + */
> + if (slice_count == 12)
> + return 0;
> +
> + return slice_count;
> }
>
> static int intel_dp_mst_find_vcpi_slots_for_bpp(struct intel_encoder
> *encoder, @@ -1524,6 +1535,7 @@ intel_dp_mst_mode_valid_ctx(struct
> drm_connector *connector,
>
> intel_dp_dsc_get_slice_count(intel_connector,
> target_clock,
> mode->hdisplay,
> +
> INTEL_OUTPUT_FORMAT_RGB,
>
> num_joined_pipes);
> }
>
> --
> 2.45.2
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