Re: [RFC 6/6] drm/i915/dp: Update pipe_bpp for DP YCbCr4:2:0 outputs

Maarten Lankhorst
2019-02-08T15:29:36Z

Op 31-01-2019 om 22:10 schreef Gwan-gyeong Mun:
> pipe_bpp value was assumed RGB therefore it was multiplied with 3.
> But YCbCr 4:2:0 requires multiplier value to 1.5 therefore it divides
> pipe_bpp to 2.
> - RGB bpp = bpc x 3
> - YCbCr 4:2:0 bpp = bpc x 1.5
>
> Signed-off-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
> ---
> drivers/gpu/drm/i915/intel_ddi.c | 7 +++++-
> drivers/gpu/drm/i915/intel_dp.c | 41 ++++++++++++++++++++++++++------
> 2 files changed, 40 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index c6aed2b06a59..7f56aa7842c1 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -1696,6 +1696,7 @@ void intel_ddi_set_pipe_settings(const struct intel_crtc_state *crtc_state)
> struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
> u32 temp;
> + int bpp;
>
> if (!intel_crtc_has_dp_encoder(crtc_state))
> return;
> @@ -1707,7 +1708,11 @@ void intel_ddi_set_pipe_settings(const struct intel_crtc_state *crtc_state)
> if (crtc_state->limited_color_range)
> temp |= TRANS_MSA_CEA_RANGE;
>
> - switch (crtc_state->pipe_bpp) {
> + bpp = crtc_state->pipe_bpp;
> + if (crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR420)
> + bpp *= 2;
> +
> + switch (bpp) {
> case 18:
> temp |= TRANS_MSA_6_BPC;
> break;
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index 3a9a5a3c33a9..734c5743e03f 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -1761,12 +1761,13 @@ static int intel_dp_compute_bpp(struct intel_dp *intel_dp,
> struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
> struct intel_connector *intel_connector = intel_dp->attached_connector;
> int bpp, bpc;
> + int bpp_divider = pipe_config->output_format == INTEL_OUTPUT_FORMAT_YCBCR420 ? 2 : 1;
>
> bpp = pipe_config->pipe_bpp;
> bpc = drm_dp_downstream_max_bpc(intel_dp->dpcd, intel_dp->downstream_ports);
>
> if (bpc > 0)
> - bpp = min(bpp, 3*bpc);
> + bpp = min(bpp, 3*bpc/bpp_divider);
>
> if (intel_dp_is_edp(intel_dp)) {
> /* Get bpp from vbt only for panels that dont have bpp in edid */
> @@ -1787,12 +1788,14 @@ intel_dp_adjust_compliance_config(struct intel_dp *intel_dp,
> struct intel_crtc_state *pipe_config,
> struct link_config_limits *limits)
> {
> + int bpp_divider = pipe_config->output_format == INTEL_OUTPUT_FORMAT_YCBCR420 ? 2 : 1;
> +
> /* For DP Compliance we override the computed bpp for the pipe */
> if (intel_dp->compliance.test_data.bpc != 0) {
> - int bpp = 3 * intel_dp->compliance.test_data.bpc;
> + int bpp = 3 * intel_dp->compliance.test_data.bpc / bpp_divider;
>
> limits->min_bpp = limits->max_bpp = bpp;
> - pipe_config->dither_force_disable = bpp == 6 * 3;
> + pipe_config->dither_force_disable = bpp == 6 * 3 / bpp_divider;
>
> DRM_DEBUG_KMS("Setting pipe_bpp to %d\n", bpp);
> }
> @@ -1826,8 +1829,9 @@ intel_dp_compute_link_config_wide(struct intel_dp *intel_dp,
> struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
> int bpp, clock, lane_count;
> int mode_rate, link_clock, link_avail;
> + int bpp_divider = pipe_config->output_format == INTEL_OUTPUT_FORMAT_YCBCR420 ? 2 : 1;
>
> - for (bpp = limits->max_bpp; bpp >= limits->min_bpp; bpp -= 2 * 3) {
> + for (bpp = limits->max_bpp; bpp >= limits->min_bpp; bpp -= 2 * 3 / bpp_divider) {
> mode_rate = intel_dp_link_required(adjusted_mode->crtc_clock,
> bpp);
>
> @@ -1862,8 +1866,9 @@ intel_dp_compute_link_config_fast(struct intel_dp *intel_dp,
> struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
> int bpp, clock, lane_count;
> int mode_rate, link_clock, link_avail;
> + int bpp_divider = pipe_config->output_format == INTEL_OUTPUT_FORMAT_YCBCR420 ? 2 : 1;
>
> - for (bpp = limits->max_bpp; bpp >= limits->min_bpp; bpp -= 2 * 3) {
> + for (bpp = limits->max_bpp; bpp >= limits->min_bpp; bpp -= 2 * 3 / bpp_divider) {
> mode_rate = intel_dp_link_required(adjusted_mode->crtc_clock,
> bpp);
>
> @@ -2009,6 +2014,7 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
> struct link_config_limits limits;
> int common_len;
> int ret;
> + int bpp_divider = pipe_config->output_format == INTEL_OUTPUT_FORMAT_YCBCR420 ? 2 : 1;
>
> common_len = intel_dp_common_len_rate_limit(intel_dp,
> intel_dp->max_link_rate);
> @@ -2022,7 +2028,7 @@ intel_dp_compute_link_config(struct intel_encoder *encoder,
> limits.min_lane_count = 1;
> limits.max_lane_count = intel_dp_max_lane_count(intel_dp);
>
> - limits.min_bpp = 6 * 3;
> + limits.min_bpp = 6 * 3 / bpp_divider;
> limits.max_bpp = intel_dp_compute_bpp(intel_dp, pipe_config);
>
> if (intel_dp_is_edp(intel_dp) && intel_dp->edp_dpcd[0] < DP_EDP_14) {
> @@ -2110,6 +2116,11 @@ intel_dp_ycbcr420_config(struct drm_connector *connector,
> }
>
> config->output_format = INTEL_OUTPUT_FORMAT_YCBCR420;
> + /* pipe_bpp value was assumed RGB therefore it was multiplied
> + * with 3. But YCbCr 4:2:0 requires multiplier value to 1.5
> + * therefore it divides pipe_bpp to 2.
> + */
> + config->pipe_bpp /= 2;
>
> /* YCBCR 420 output conversion needs a scaler */
> if (skl_update_scaler_crtc(config)) {
> @@ -4446,7 +4457,23 @@ intel_pixel_encoding_setup_vsc(struct intel_dp *intel_dp,
> * 011b = 12bpc.
> * 100b = 16bpc.
> */
> - vsc_sdp.DB17 = 0x1;
> + switch (crtc_state->pipe_bpp) {
> + case 12: /* 8bpc */
> + vsc_sdp.DB17 = 0x1;
> + break;
> + case 15: /* 10bpc */
> + vsc_sdp.DB17 = 0x2;
> + break;
> + case 18: /* 12bpc */
> + vsc_sdp.DB17 = 0x3;
> + break;
> + case 24: /* 16bpc */
> + vsc_sdp.DB17 = 0x4;
> + break;
> + default:
> + DRM_DEBUG_KMS("Invalid bpp value '%d'\n", crtc_state->pipe_bpp);
> + break;
> + }
>
> /*
> * Content Type (Bits 2:0)

For patch 2, 3, 5, and 6:

Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>