On Fri, Oct 28, 2022 at 03:14:05PM +0530, Ankit Nautiyal wrote:
> The decision to use DFP output format conversion capabilities should be
> during compute_config phase.
>
> This patch uses the members of intel_dp->dfp to only store the
> format conversion capabilities of the DP device and uses the crtc_state
> sink_format member, to program the protocol-converter for
> colorspace/format conversion.
>
> v2: Use sink_format to determine the color conversion config for the
> pcon (Ville).
>
> v3: Fix typo: missing 'break' in switch case (lkp kernel test robot).
>
> v4: Add helper to check if DP supports YCBCR420.
>
> Signed-off-by: Ankit Nautiyal <ankit.k.nauti...@intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_dp.c | 122 ++++++++++++++++--------
> 1 file changed, 84 insertions(+), 38 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
> b/drivers/gpu/drm/i915/display/intel_dp.c
> index 0e4f7b467970..95d0c653db7f 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> @@ -790,6 +790,7 @@ intel_dp_output_format(struct intel_connector *connector,
> enum intel_output_format sink_format)
> {
> struct intel_dp *intel_dp = intel_attached_dp(connector);
> + struct drm_i915_private *i915 = dp_to_i915(intel_dp);
>
> if (!connector->base.ycbcr_420_allowed ||
> sink_format != INTEL_OUTPUT_FORMAT_YCBCR420)
> @@ -799,6 +800,10 @@ intel_dp_output_format(struct intel_connector *connector,
> intel_dp->dfp.ycbcr_444_to_420)
> return INTEL_OUTPUT_FORMAT_RGB;
>
> + /* Prefer 4:2:0 passthrough over 4:4:4->4:2:0 conversion */
> + if (DISPLAY_VER(i915) >= 11 && intel_dp->dfp.ycbcr420_passthrough)
> + return INTEL_OUTPUT_FORMAT_YCBCR420;
> +
> if (intel_dp->dfp.ycbcr_444_to_420)
> return INTEL_OUTPUT_FORMAT_YCBCR444;
> else
The else branch here is also 420, so the whole logic
here doesn't seem to flow entirely sensibly.
Thinking a bit more abstractly, could we restate
this whole problem as something more like this?
if (source_can_output(sink_format))
return sink_format;
if (source_can_output(RGB) &&
dfp_can_convert_from_rgb(sink_format))
return RGB;
if (source_can_output(YCBCR444) &&
dfp_can_convert_from_ycbcr444(sink_format))
return YCBCR444;
> @@ -2668,6 +2673,8 @@ void intel_dp_configure_protocol_converter(struct
> intel_dp *intel_dp,
> const struct intel_crtc_state
> *crtc_state)
> {
> struct drm_i915_private *i915 = dp_to_i915(intel_dp);
> + bool ycbcr444_to_420 = false;
> + bool rgb_to_ycbcr = false;
> u8 tmp;
>
> if (intel_dp->dpcd[DP_DPCD_REV] < 0x13)
> @@ -2684,8 +2691,35 @@ void intel_dp_configure_protocol_converter(struct
> intel_dp *intel_dp,
> drm_dbg_kms(&i915->drm, "Failed to %s protocol converter HDMI
> mode\n",
> str_enable_disable(intel_dp->has_hdmi_sink));
>
> - tmp = crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR444 &&
> - intel_dp->dfp.ycbcr_444_to_420 ?
> DP_CONVERSION_TO_YCBCR420_ENABLE : 0;
> + if (crtc_state->sink_format == INTEL_OUTPUT_FORMAT_YCBCR420) {
> + switch (crtc_state->output_format) {
> + case INTEL_OUTPUT_FORMAT_YCBCR420:
> + /*
> + * sink_format is YCBCR420, output_format is also
> YCBCR420:
> + * Passthrough.
> + */
> + break;
> + case INTEL_OUTPUT_FORMAT_YCBCR444:
> + /*
> + * sink_format is YCBCR420, output_format is YCBCR444:
> + * Downsample.
> + */
> + ycbcr444_to_420 = true;
> + break;
> + case INTEL_OUTPUT_FORMAT_RGB:
> + /*
> + * sink_format is YCBCR420, output_format is RGB:
> + * Convert to YCBCR444 and Downsample.
> + */
> + rgb_to_ycbcr = true;
> + ycbcr444_to_420 = true;
> + break;
> + default:
> + break;
> + }
> + }
> +
> + tmp = ycbcr444_to_420 ? DP_CONVERSION_TO_YCBCR420_ENABLE : 0;
>
> if (drm_dp_dpcd_writeb(&intel_dp->aux,
> DP_PROTOCOL_CONVERTER_CONTROL_1, tmp) != 1)
> @@ -2693,13 +2727,12 @@ void intel_dp_configure_protocol_converter(struct
> intel_dp *intel_dp,
> "Failed to %s protocol converter YCbCr 4:2:0
> conversion mode\n",
> str_enable_disable(intel_dp->dfp.ycbcr_444_to_420));
>
> - tmp = intel_dp->dfp.rgb_to_ycbcr ?
> - DP_CONVERSION_BT709_RGB_YCBCR_ENABLE : 0;
> + tmp = rgb_to_ycbcr ? DP_CONVERSION_BT709_RGB_YCBCR_ENABLE : 0;
>
> if (drm_dp_pcon_convert_rgb_to_ycbcr(&intel_dp->aux, tmp) < 0)
> drm_dbg_kms(&i915->drm,
> - "Failed to %s protocol converter RGB->YCbCr
> conversion mode\n",
> - str_enable_disable(tmp));
> + "Failed to %s protocol converter RGB->YCbCr
> conversion mode\n",
> + str_enable_disable(tmp));
> }
>
> bool intel_dp_get_colorimetry_status(struct intel_dp *intel_dp)
> @@ -4544,57 +4577,70 @@ intel_dp_update_dfp(struct intel_dp *intel_dp,
> intel_dp_get_pcon_dsc_cap(intel_dp);
> }
>
> -static void
> -intel_dp_update_420(struct intel_dp *intel_dp)
> +static bool
> +intel_dp_can_ycbcr420(struct intel_connector *connector)
> {
> + struct intel_dp *intel_dp = intel_attached_dp(connector);
> struct drm_i915_private *i915 = dp_to_i915(intel_dp);
> - struct intel_connector *connector = intel_dp->attached_connector;
> - bool is_branch, ycbcr_420_passthrough, ycbcr_444_to_420, rgb_to_ycbcr;
> + bool is_branch = drm_dp_is_branch(intel_dp->dpcd);
>
> /* No YCbCr output support on gmch platforms */
> if (HAS_GMCH(i915))
> - return;
> + return false;
>
> /*
> * ILK doesn't seem capable of DP YCbCr output. The
> * displayed image is severly corrupted. SNB+ is fine.
> */
> if (IS_IRONLAKE(i915))
> - return;
> + return false;
> + /*
> + * For Display < 11, YCBCR420 output possible only
> + * if DFP supports 444->420 conversion.
> + */
> + if (DISPLAY_VER(i915) < 11)
> + return is_branch && intel_dp->dfp.ycbcr_444_to_420;
> +
> + /*
> + * For Display > 11:
> + * If not a branch device, can support YCBCR420.
> + */
> + if (!is_branch)
> + return true;
> +
> + /*
> + * If branch device then either:
> + * 1. PCONs should support YCBCR420 Passthrough
> + * i.e.Source uses CSC, scaler to convert RGB->YCBCR420 and
> + * sends YCBCR420 to PCON. PCON 'passrthrough' YCBCR420 to sink.
> + * Or
> + * 2. PCONs should support 444->420
> + * (Source sends YCBCR444 PCON converts YCBCR444->420)
> + * (Source sends RGB4444 PCON converts RGB->YCBCR444 and
> YCBCR444->YCBCR420)
> + */
> + return intel_dp->dfp.ycbcr420_passthrough ||
> intel_dp->dfp.ycbcr_444_to_420;
> +}
>
> - is_branch = drm_dp_is_branch(intel_dp->dpcd);
> - ycbcr_420_passthrough =
> +static void
> +intel_dp_update_420(struct intel_dp *intel_dp)
> +{
> + struct drm_i915_private *i915 = dp_to_i915(intel_dp);
> + struct intel_connector *connector = intel_dp->attached_connector;
> +
> + intel_dp->dfp.ycbcr420_passthrough =
> drm_dp_downstream_420_passthrough(intel_dp->dpcd,
> intel_dp->downstream_ports);
> /* on-board LSPCON always assumed to support 4:4:4->4:2:0 conversion */
> - ycbcr_444_to_420 =
> + intel_dp->dfp.ycbcr_444_to_420 =
> dp_to_dig_port(intel_dp)->lspcon.active ||
> drm_dp_downstream_444_to_420_conversion(intel_dp->dpcd,
>
> intel_dp->downstream_ports);
> - rgb_to_ycbcr = drm_dp_downstream_rgb_to_ycbcr_conversion(intel_dp->dpcd,
> -
> intel_dp->downstream_ports,
> -
> DP_DS_HDMI_BT709_RGB_YCBCR_CONV);
> -
> - if (DISPLAY_VER(i915) >= 11) {
> - /* Let PCON convert from RGB->YCbCr if possible */
> - if (is_branch && rgb_to_ycbcr && ycbcr_444_to_420) {
> - intel_dp->dfp.rgb_to_ycbcr = true;
> - intel_dp->dfp.ycbcr_444_to_420 = true;
> - connector->base.ycbcr_420_allowed = true;
> - } else {
> - /* Prefer 4:2:0 passthrough over 4:4:4->4:2:0 conversion */
> - intel_dp->dfp.ycbcr_444_to_420 =
> - ycbcr_444_to_420 && !ycbcr_420_passthrough;
> + intel_dp->dfp.rgb_to_ycbcr =
> + drm_dp_downstream_rgb_to_ycbcr_conversion(intel_dp->dpcd,
> +
> intel_dp->downstream_ports,
> +
> DP_DS_HDMI_BT709_RGB_YCBCR_CONV);
>
> - connector->base.ycbcr_420_allowed =
> - !is_branch || ycbcr_444_to_420 ||
> ycbcr_420_passthrough;
> - }
> - } else {
> - /* 4:4:4->4:2:0 conversion is the only way */
> - intel_dp->dfp.ycbcr_444_to_420 = ycbcr_444_to_420;
> -
> - connector->base.ycbcr_420_allowed = ycbcr_444_to_420;
> - }
> + connector->base.ycbcr_420_allowed = intel_dp_can_ycbcr420(connector);
>
> drm_dbg_kms(&i915->drm,
> "[CONNECTOR:%d:%s] RGB->YcbCr conversion? %s, YCbCr 4:2:0
> allowed? %s, YCbCr 4:4:4->4:2:0 conversion? %s\n",
> --
> 2.25.1
--
Ville Syrjälä
Intel
