[PATCH v2 13/13] drm/i915: Configure PCON for DSC1.1 to DSC1.2 encoding
Shankar, Uma
uma.shankar at intel.com
Wed Nov 25 20:45:05 UTC 2020
> -----Original Message-----
> From: Nautiyal, Ankit K <ankit.k.nautiyal at intel.com>
> Sent: Sunday, November 1, 2020 3:37 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: dri-devel at lists.freedesktop.org; Shankar, Uma <uma.shankar at intel.com>;
> Kulkarni, Vandita <vandita.kulkarni at intel.com>; ville.syrjala at linux.intel.com;
> Sharma, Swati2 <swati2.sharma at intel.com>
> Subject: [PATCH v2 13/13] drm/i915: Configure PCON for DSC1.1 to DSC1.2
> encoding
May be good to append i915/ with display as well.
> When a source supporting DSC1.1 is connected to DSC1.2 HDMI2.1 sink via DP
> HDMI2.1 PCON, the PCON can be configured to decode the
> DSC1.1 compressed stream and encode to DSC1.2. It then sends the
> DSC1.2 compressed stream to the HDMI2.1 sink.
>
> This patch configures the PCON for DSC1.1 to DSC1.2 encoding, based on the
> PCON's DSC encoder capablities and HDMI2.1 sink's DSC decoder capabilities.
>
> v2: Rebase
>
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_ddi.c | 1 +
> drivers/gpu/drm/i915/display/intel_dp.c | 128 ++++++++++++++++++++++-
> drivers/gpu/drm/i915/display/intel_dp.h | 2 +
> 3 files changed, 129 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
> b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 3e76fb1117df..dbf28d021d08 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -3493,6 +3493,7 @@ static void tgl_ddi_pre_enable_dp(struct
> intel_atomic_state *state,
> intel_dp_sink_set_fec_ready(intel_dp, crtc_state);
>
> intel_dp_check_frl_training(intel_dp);
> + intel_dp_pcon_dsc_configure(intel_dp, crtc_state);
These are called here unconditionally, I think we should invoke them only if
we are driving a pcon and not a native DP.
>
> /*
> * 7.i Follow DisplayPort specification training sequence (see notes for
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index 2e7ddb062efe..bc1f1afc35ad 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -788,6 +788,16 @@ intel_dp_mode_valid(struct drm_connector *connector,
> target_clock,
> mode->hdisplay);
> }
> +
> + /*
> + * TODO: If its a PCON with HDMI sink:
> + * Assumption : Source only supports DSC1.1
> + *
> + * If HDMI supports DSC 1.2 but PCON does not support
> + * DSC1.1->DSC1.2 encoding Then return MODE_CLOCK_HIGH.
> + * Otherwise check if the mode can be applied according to
> + * DSC capablities of the PCON and HDMI Sink combine.
> + */
> }
>
> if ((mode_rate > max_rate && !(dsc_max_output_bpp &&
> dsc_slice_count)) || @@ -3936,9 +3946,21 @@ static int
> intel_dp_hdmi_sink_max_frl(struct intel_dp *intel_dp) {
> struct intel_connector *intel_connector = intel_dp->attached_connector;
> struct drm_connector *connector = &intel_connector->base;
> + int max_frl_rate;
> + int max_lanes, rate_per_lane;
> + int max_dsc_lanes, dsc_rate_per_lane;
> +
> + max_lanes = connector->display_info.hdmi.max_lanes;
> + rate_per_lane = connector->display_info.hdmi.max_frl_rate_per_lane;
> + max_frl_rate = max_lanes * rate_per_lane;
> +
> + if (connector->display_info.hdmi.dsc_cap.v_1p2) {
> + max_dsc_lanes = connector-
> >display_info.hdmi.dsc_cap.max_lanes;
> + dsc_rate_per_lane = connector-
> >display_info.hdmi.dsc_cap.max_frl_rate_per_lane;
> + max_frl_rate = min(max_frl_rate, max_dsc_lanes *
> dsc_rate_per_lane);
> + }
>
> - return (connector->display_info.hdmi.max_frl_rate_per_lane *
> - connector->display_info.hdmi.max_lanes);
> + return max_frl_rate;
> }
>
> static int intel_dp_pcon_start_frl_training(struct intel_dp *intel_dp) @@ -
> 4071,6 +4093,106 @@ void intel_dp_check_frl_training(struct intel_dp *intel_dp)
> }
> }
>
> +static int
> +intel_dp_pcon_dsc_enc_slice_height(const struct intel_crtc_state
> +*crtc_state) {
> +
> + int vactive = crtc_state->hw.adjusted_mode.vdisplay;
> +
> + return intel_hdmi_dsc_get_slice_height(vactive);
> +}
> +
> +static int
> +intel_dp_pcon_dsc_enc_slices(struct intel_dp *intel_dp,
> + const struct intel_crtc_state *crtc_state) {
> + struct intel_connector *intel_connector = intel_dp->attached_connector;
> + struct drm_connector *connector = &intel_connector->base;
> + int hdmi_throughput = connector-
> >display_info.hdmi.dsc_cap.clk_per_slice;
> + int hdmi_max_slices = connector->display_info.hdmi.dsc_cap.max_slices;
> + int pcon_max_slices = drm_dp_pcon_dsc_max_slices(intel_dp-
> >pcon_dsc_dpcd);
> + int pcon_max_slice_width =
> +drm_dp_pcon_dsc_max_slice_width(intel_dp->pcon_dsc_dpcd);
> +
> +
> + return intel_hdmi_dsc_get_num_slices(crtc_state, pcon_max_slices,
> + pcon_max_slice_width,
> + hdmi_max_slices, hdmi_throughput); }
> +
> +static int
> +intel_dp_pcon_dsc_enc_bpp(struct intel_dp *intel_dp,
> + const struct intel_crtc_state *crtc_state,
> + int num_slices, int slice_width)
> +{
> + struct intel_connector *intel_connector = intel_dp->attached_connector;
> + struct drm_connector *connector = &intel_connector->base;
> + int output_format = crtc_state->output_format;
> + bool hdmi_all_bpp = connector->display_info.hdmi.dsc_cap.all_bpp;
> + int pcon_fractional_bpp = drm_dp_pcon_dsc_bpp_incr(intel_dp-
> >pcon_dsc_dpcd);
> + int hdmi_max_chunk_bytes =
> + connector->display_info.hdmi.dsc_cap.total_chunk_kbytes *
> 1024;
> +
> + return intel_hdmi_dsc_get_bpp(pcon_fractional_bpp, slice_width,
> + num_slices, output_format, hdmi_all_bpp,
> + hdmi_max_chunk_bytes);
> +}
> +
> +void
> +intel_dp_pcon_dsc_configure(struct intel_dp *intel_dp,
> + const struct intel_crtc_state *crtc_state) {
> + u8 pps_param[6];
> + u8 buf;
> + int version_major, version_minor;
> + int slice_height;
> + int slice_width;
> + int num_slices;
> + int bits_per_pixel;
> + int ret;
> + struct intel_connector *intel_connector = intel_dp->attached_connector;
> + struct drm_i915_private *i915 = dp_to_i915(intel_dp);
> + struct drm_connector *connector = &intel_connector->base;
> + bool hdmi_is_dsc_1_2 = connector->display_info.hdmi.dsc_cap.v_1p2;
This may be NULL, please add a check before using it.
> +
> +
> + buf = intel_dp->pcon_dsc_dpcd[DP_PCON_DSC_VERSION -
> DP_PCON_DSC_ENCODER];
> + version_major = (buf & DP_PCON_DSC_MAJOR_MASK) >>
> DP_PCON_DSC_MAJOR_SHIFT;
> + version_minor = (buf & DP_PCON_DSC_MINOR_MASK) >>
> +DP_PCON_DSC_MINOR_SHIFT;
> +
> +
> + /* Only if PCON encoder and HDMI decoder both support DSC 1.2 */
> + if ((version_major != 1 || version_minor != 2) ||
> + (!hdmi_is_dsc_1_2))
> + return;
> +
> + slice_height = intel_dp_pcon_dsc_enc_slice_height(crtc_state);
> + if (!slice_height)
> + return;
> +
> + num_slices = intel_dp_pcon_dsc_enc_slices(intel_dp, crtc_state);
> + if (!num_slices)
> + return;
> +
> + slice_width = DIV_ROUND_UP(crtc_state->hw.adjusted_mode.hdisplay,
> + num_slices);
> +
> + bits_per_pixel = intel_dp_pcon_dsc_enc_bpp(intel_dp, crtc_state,
> + num_slices, slice_width);
> + if (!bits_per_pixel)
> + return;
> +
> + pps_param[0] = slice_height >> 8;
> + pps_param[1] = slice_height & 0xFF;
First we have LSB, so isn't the order be reversed ?
> + pps_param[2] = slice_width >> 8;
> + pps_param[3] = slice_width & 0xFF;
Same here.
> + pps_param[4] = bits_per_pixel >> 8;
> + pps_param[5] = bits_per_pixel & 0xFF;
Last 2:7 are reserved, so adjust the mask accordingly.
> +
> + ret = drm_dp_pcon_pps_override_param(&intel_dp->aux, pps_param);
> + if (ret < 0)
> + drm_dbg_kms(&i915->drm, "Failed to set pcon DSC\n"); }
> +
> static void
> g4x_set_link_train(struct intel_dp *intel_dp,
> const struct intel_crtc_state *crtc_state, @@ -4202,6 +4324,7
> @@ static void intel_enable_dp(struct intel_atomic_state *state,
> intel_dp_set_power(intel_dp, DP_SET_POWER_D0);
> intel_dp_configure_protocol_converter(intel_dp);
> intel_dp_check_frl_training(intel_dp);
> + intel_dp_pcon_dsc_configure(intel_dp, pipe_config);
> intel_dp_start_link_train(intel_dp, pipe_config);
> intel_dp_stop_link_train(intel_dp, pipe_config);
>
> @@ -6149,6 +6272,7 @@ int intel_dp_retrain_link(struct intel_encoder
> *encoder,
> continue;
>
> intel_dp_check_frl_training(intel_dp);
> + intel_dp_pcon_dsc_configure(intel_dp, crtc_state);
> intel_dp_start_link_train(intel_dp, crtc_state);
> intel_dp_stop_link_train(intel_dp, crtc_state);
> break;
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.h
> b/drivers/gpu/drm/i915/display/intel_dp.h
> index a667d3f578d6..3515e057447e 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.h
> +++ b/drivers/gpu/drm/i915/display/intel_dp.h
> @@ -144,5 +144,7 @@ void intel_dp_sync_state(struct intel_encoder *encoder,
> const struct intel_crtc_state *crtc_state);
>
> void intel_dp_check_frl_training(struct intel_dp *intel_dp);
> +void intel_dp_pcon_dsc_configure(struct intel_dp *intel_dp,
> + const struct intel_crtc_state *crtc_state);
>
> #endif /* __INTEL_DP_H__ */
> --
> 2.17.1
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