> MTL+ supports fractional compressed bits_per_pixel, with precision of
> 1/16. This compressed bpp is stored in U6.4 format.
> Accommodate this precision while computing m_n values.
>
> v1:
> Replace the computation of 'data_clock' with 'data_clock =
> DIV_ROUND_UP(data_clock, 16).' (Sui Jingfeng).
>
> v2:
> Rebase and pass bits_per_pixel in U6.4 format.
>
LGTM.
Reviewed-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx>
> Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani@xxxxxxxxx>
> Reviewed-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
> Reviewed-by: Sui Jingfeng <suijingfeng@xxxxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_display.c | 4 ++--
> drivers/gpu/drm/i915/display/intel_dp.c | 16 ++++++++--------
> drivers/gpu/drm/i915/display/intel_dp_mst.c | 14 +++++++-------
> drivers/gpu/drm/i915/display/intel_fdi.c | 3 ++-
> 4 files changed, 19 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> b/drivers/gpu/drm/i915/display/intel_display.c
> index b4a8e3087e50..125903007a29 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -2415,12 +2415,12 @@ add_bw_alloc_overhead(int link_clock, int
> bw_overhead, }
>
> void
> -intel_link_compute_m_n(u16 bits_per_pixel, int nlanes,
> +intel_link_compute_m_n(u16 bits_per_pixel_x16, int nlanes,
> int pixel_clock, int link_clock,
> int bw_overhead,
> struct intel_link_m_n *m_n)
> {
> - u32 data_clock = bits_per_pixel * pixel_clock;
> + u32 data_clock = DIV_ROUND_UP(bits_per_pixel_x16 * pixel_clock,
> 16);
> u32 data_m;
> u32 data_n;
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index 4ad3718c3c7d..246f50d1f030 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -2663,7 +2663,7 @@ static bool can_enable_drrs(struct intel_connector
> *connector, static void intel_dp_drrs_compute_config(struct intel_connector
> *connector,
> struct intel_crtc_state *pipe_config,
> - int link_bpp)
> + int link_bpp_x16)
> {
> struct drm_i915_private *i915 = to_i915(connector->base.dev);
> const struct drm_display_mode *downclock_mode = @@ -2688,7
> +2688,7 @@ intel_dp_drrs_compute_config(struct intel_connector
> *connector,
> if (pipe_config->splitter.enable)
> pixel_clock /= pipe_config->splitter.link_count;
>
> - intel_link_compute_m_n(link_bpp, pipe_config->lane_count,
> pixel_clock,
> + intel_link_compute_m_n(link_bpp_x16, pipe_config->lane_count,
> +pixel_clock,
> pipe_config->port_clock,
> intel_dp_bw_fec_overhead(pipe_config-
> >fec_enable),
> &pipe_config->dp_m2_n2);
> @@ -2792,7 +2792,7 @@ intel_dp_compute_config(struct intel_encoder
> *encoder,
> struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
> const struct drm_display_mode *fixed_mode;
> struct intel_connector *connector = intel_dp->attached_connector;
> - int ret = 0, link_bpp;
> + int ret = 0, link_bpp_x16;
>
> if (HAS_PCH_SPLIT(dev_priv) && !HAS_DDI(dev_priv) && encoder-
> >port != PORT_A)
> pipe_config->has_pch_encoder = true;
> @@ -2841,10 +2841,10 @@ intel_dp_compute_config(struct intel_encoder
> *encoder,
> drm_dp_enhanced_frame_cap(intel_dp->dpcd);
>
> if (pipe_config->dsc.compression_enable)
> - link_bpp = to_bpp_int(pipe_config-
> >dsc.compressed_bpp_x16);
> + link_bpp_x16 = pipe_config->dsc.compressed_bpp_x16;
> else
> - link_bpp = intel_dp_output_bpp(pipe_config-
> >output_format,
> - pipe_config->pipe_bpp);
> + link_bpp_x16 =
> to_bpp_x16(intel_dp_output_bpp(pipe_config->output_format,
> + pipe_config-
> >pipe_bpp));
>
> if (intel_dp->mso_link_count) {
> int n = intel_dp->mso_link_count;
> @@ -2868,7 +2868,7 @@ intel_dp_compute_config(struct intel_encoder
> *encoder,
>
> intel_dp_audio_compute_config(encoder, pipe_config, conn_state);
>
> - intel_link_compute_m_n(link_bpp,
> + intel_link_compute_m_n(link_bpp_x16,
> pipe_config->lane_count,
> adjusted_mode->crtc_clock,
> pipe_config->port_clock,
> @@ -2884,7 +2884,7 @@ intel_dp_compute_config(struct intel_encoder
> *encoder,
>
> intel_vrr_compute_config(pipe_config, conn_state);
> intel_psr_compute_config(intel_dp, pipe_config, conn_state);
> - intel_dp_drrs_compute_config(connector, pipe_config, link_bpp);
> + intel_dp_drrs_compute_config(connector, pipe_config,
> link_bpp_x16);
> intel_dp_compute_vsc_sdp(intel_dp, pipe_config, conn_state);
> intel_dp_compute_hdr_metadata_infoframe_sdp(intel_dp,
> pipe_config, conn_state);
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 31461ea25f7c..5c7e9d296483 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -70,7 +70,7 @@ static int intel_dp_mst_check_constraints(struct
> drm_i915_private *i915, int bpp
>
> static int intel_dp_mst_bw_overhead(const struct intel_crtc_state *crtc_state,
> const struct intel_connector *connector,
> - bool ssc, bool dsc, int bpp)
> + bool ssc, bool dsc, int bpp_x16)
> {
> const struct drm_display_mode *adjusted_mode =
> &crtc_state->hw.adjusted_mode;
> @@ -94,7 +94,7 @@ static int intel_dp_mst_bw_overhead(const struct
> intel_crtc_state *crtc_state,
> overhead = drm_dp_bw_overhead(crtc_state->lane_count,
> adjusted_mode->hdisplay,
> dsc_slice_count,
> - to_bpp_x16(bpp),
> + bpp_x16,
> flags);
>
> /*
> @@ -107,16 +107,16 @@ static int intel_dp_mst_bw_overhead(const struct
> intel_crtc_state *crtc_state, static void intel_dp_mst_compute_m_n(const
> struct intel_crtc_state *crtc_state,
> const struct intel_connector *connector,
> bool ssc, bool dsc,
> - int bpp,
> + int bpp_x16,
> struct intel_link_m_n *m_n)
> {
> const struct drm_display_mode *adjusted_mode =
> &crtc_state->hw.adjusted_mode;
> int overhead = intel_dp_mst_bw_overhead(crtc_state,
> connector,
> - ssc, dsc, bpp);
> + ssc, dsc, bpp_x16);
>
> - intel_link_compute_m_n(bpp, crtc_state->lane_count,
> + intel_link_compute_m_n(bpp_x16, crtc_state->lane_count,
> adjusted_mode->crtc_clock,
> crtc_state->port_clock,
> overhead,
> @@ -180,9 +180,9 @@ static int intel_dp_mst_find_vcpi_slots_for_bpp(struct
> intel_encoder *encoder,
> link_bpp = dsc ? bpp :
> intel_dp_output_bpp(crtc_state->output_format,
> bpp);
>
> - intel_dp_mst_compute_m_n(crtc_state, connector, false, dsc,
> link_bpp,
> + intel_dp_mst_compute_m_n(crtc_state, connector, false, dsc,
> +to_bpp_x16(link_bpp),
> &crtc_state->dp_m_n);
> - intel_dp_mst_compute_m_n(crtc_state, connector, true, dsc,
> link_bpp,
> + intel_dp_mst_compute_m_n(crtc_state, connector, true, dsc,
> +to_bpp_x16(link_bpp),
> &remote_m_n);
>
> /*
> diff --git a/drivers/gpu/drm/i915/display/intel_fdi.c
> b/drivers/gpu/drm/i915/display/intel_fdi.c
> index 1d87fbc1e813..295a0f24ebbf 100644
> --- a/drivers/gpu/drm/i915/display/intel_fdi.c
> +++ b/drivers/gpu/drm/i915/display/intel_fdi.c
> @@ -339,7 +339,8 @@ int ilk_fdi_compute_config(struct intel_crtc *crtc,
>
> pipe_config->fdi_lanes = lane;
>
> - intel_link_compute_m_n(pipe_config->pipe_bpp, lane, fdi_dotclock,
> + intel_link_compute_m_n(to_bpp_x16(pipe_config->pipe_bpp),
> + lane, fdi_dotclock,
> link_bw,
> intel_dp_bw_fec_overhead(false),
> &pipe_config->fdi_m_n);
> --
> 2.40.1
