On Tue, 27 May 2025, Jani Nikula <jani.nik...@linux.intel.com> wrote:
>On Tue, 27 May 2025, Lee Shawn C <shawn.c....@intel.com> wrote:
>> A DSC setting has been available in VBT since version 251, which
>> allows users to enable or disable the DSC feature based on their system
>> design.
>> With this in mind, DP driver should reference this setting and avoid
>> enabling DSC if this value is not allowed.
>>
>> Cc: Shankar Uma <uma.shan...@intel.com>
>> Cc: Jani Nikula <jani.nik...@linux.intel.com>
>> Cc: Ville Syrjälä <ville.syrj...@linux.intel.com>
>> Signed-off-by: Lee Shawn C <shawn.c....@intel.com>
>> ---
>> drivers/gpu/drm/i915/display/intel_bios.c | 8 ++++++++
>> drivers/gpu/drm/i915/display/intel_bios.h | 1 +
>> drivers/gpu/drm/i915/display/intel_dp.c | 12 +++++++++---
>> drivers/gpu/drm/i915/display/intel_dp.h | 2 +-
>> drivers/gpu/drm/i915/display/intel_dp_mst.c | 2 +-
>> 5 files changed, 20 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c
>> b/drivers/gpu/drm/i915/display/intel_bios.c
>> index ba7b8938b17c..f08dd54fe4d4 100644
>> --- a/drivers/gpu/drm/i915/display/intel_bios.c
>> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
>> @@ -3548,6 +3548,14 @@ bool intel_bios_get_dsc_params(struct intel_encoder
>> *encoder,
>> return false;
>> }
>>
>> +bool intel_bios_encoder_ext_display_dsc_disabled(const struct
>> +intel_bios_encoder_data *devdata)
>
>Prefer positive instead of negative, and follow naming conventions.
>
>intel_bios_encoder_supports_dsc().
>
Sure! I will rename this function.
>> +{
>> + if (!devdata || devdata->display->vbt.version < 251)
>> + return false;
>> +
>> + return devdata->child.disable_compression_for_ext_disp;
>> +}
>> +
>> static const u8 adlp_aux_ch_map[] = {
>> [AUX_CH_A] = DP_AUX_A,
>> [AUX_CH_B] = DP_AUX_B,
>> diff --git a/drivers/gpu/drm/i915/display/intel_bios.h
>> b/drivers/gpu/drm/i915/display/intel_bios.h
>> index 6cd7a011b8c4..901ba63e205d 100644
>> --- a/drivers/gpu/drm/i915/display/intel_bios.h
>> +++ b/drivers/gpu/drm/i915/display/intel_bios.h
>> @@ -258,6 +258,7 @@ bool
>> intel_bios_encoder_supports_dp_dual_mode(const struct
>> intel_bios_encoder_da bool intel_bios_encoder_is_lspcon(const struct
>> intel_bios_encoder_data *devdata); bool
>> intel_bios_encoder_lane_reversal(const struct intel_bios_encoder_data
>> *devdata); bool intel_bios_encoder_hpd_invert(const struct
>> intel_bios_encoder_data *devdata);
>> +bool intel_bios_encoder_ext_display_dsc_disabled(const struct
>> +intel_bios_encoder_data *devdata);
>> enum port intel_bios_encoder_port(const struct
>> intel_bios_encoder_data *devdata); enum aux_ch
>> intel_bios_dp_aux_ch(const struct intel_bios_encoder_data *devdata);
>> int intel_bios_dp_boost_level(const struct intel_bios_encoder_data
>> *devdata); diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
>> b/drivers/gpu/drm/i915/display/intel_dp.c
>> index 640c43bf62d4..eb1e6de0148a 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>> @@ -1389,9 +1389,11 @@ int intel_dp_num_joined_pipes(struct intel_dp
>> *intel_dp,
>> return 1;
>> }
>>
>> -bool intel_dp_has_dsc(const struct intel_connector *connector)
>> +bool intel_dp_has_dsc(struct intel_dp *intel_dp,
>
>There's no need to pass that in.
>
intel_bios_encoder_supports_dsc() need intel_bios_encoder_data.
That's why we pass intel_dp and use it to get ecoder data.
Do you mean we can get encoder data from intel_connector?
>> + const struct intel_connector *connector)
>> {
>> struct intel_display *display = to_intel_display(connector);
>> + struct intel_encoder *encoder = &dp_to_dig_port(intel_dp)->base;
>>
>> if (!HAS_DSC(display))
>> return false;
>> @@ -1403,6 +1405,10 @@ bool intel_dp_has_dsc(const struct intel_connector
>> *connector)
>> connector->panel.vbt.edp.dsc_disable)
>> return false;
>>
>> + if (connector->base.connector_type == DRM_MODE_CONNECTOR_DisplayPort
>> +&&
>
>It's just absolutely bonkers that the field is for external HDMI/DP, there's a
>separate field for eDP DSC disable, and there's a separate field for DSI DSC.
>
>Anyway, I am wondering if the output type check should be in
>intel_bios_encoder_supports_dsc() instead.
>
>(intel_bios_encoder_supports_dp() && !intel_bios_encoder_supports_edp()) ||
>intel_bios_encoder_supports_hdmi().
>
Sounds good! Let's move this checking into intel_bios_encoder_supports_dsc().
Best regards,
Shawn
>BR,
>Jani.
>
>> + intel_bios_encoder_ext_display_dsc_disabled(encoder->devdata))
>> + return false;
>> +
>> if (!drm_dp_sink_supports_dsc(connector->dp.dsc_dpcd))
>> return false;
>>
>> @@ -1463,7 +1469,7 @@ intel_dp_mode_valid(struct drm_connector *_connector,
>> mode_rate = intel_dp_link_required(target_clock,
>>
>> intel_dp_mode_min_output_bpp(connector, mode));
>>
>> - if (intel_dp_has_dsc(connector)) {
>> + if (intel_dp_has_dsc(intel_dp, connector)) {
>> enum intel_output_format sink_format, output_format;
>> int pipe_bpp;
>>
>> @@ -1650,7 +1656,7 @@ bool intel_dp_supports_dsc(struct intel_dp *intel_dp,
>> const struct intel_connector *connector,
>> const struct intel_crtc_state *crtc_state) {
>> - if (!intel_dp_has_dsc(connector))
>> + if (!intel_dp_has_dsc(intel_dp, connector))
>> return false;
>>
>> if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP) && diff --git
>> a/drivers/gpu/drm/i915/display/intel_dp.h
>> b/drivers/gpu/drm/i915/display/intel_dp.h
>> index 742ae26ac4a9..309dad5b1b47 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp.h
>> +++ b/drivers/gpu/drm/i915/display/intel_dp.h
>> @@ -83,7 +83,7 @@ void intel_dp_audio_compute_config(struct
>> intel_encoder *encoder, bool intel_dp_has_hdmi_sink(struct intel_dp
>> *intel_dp); bool intel_dp_is_edp(struct intel_dp *intel_dp); bool
>> intel_dp_is_uhbr(const struct intel_crtc_state *crtc_state); -bool
>> intel_dp_has_dsc(const struct intel_connector *connector);
>> +bool intel_dp_has_dsc(struct intel_dp *intel_dp, const struct
>> +intel_connector *connector);
>> int intel_dp_link_symbol_size(int rate); int
>> intel_dp_link_symbol_clock(int rate); bool
>> intel_dp_is_port_edp(struct intel_display *display, enum port port);
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c
>> b/drivers/gpu/drm/i915/display/intel_dp_mst.c
>> index c1fd6aceec2c..4f18059d9913 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
>> @@ -1508,7 +1508,7 @@ mst_connector_mode_valid_ctx(struct drm_connector
>> *_connector,
>> return 0;
>> }
>>
>> - if (intel_dp_has_dsc(connector)) {
>> + if (intel_dp_has_dsc(intel_dp, connector)) {
>> /*
>> * TBD pass the connector BPC,
>> * for now U8_MAX so that max BPC on that platform would be
>> picked
>
>--
>Jani Nikula, Intel
>
