Re: [Intel-gfx] [PATCH 1/5] drm/i915/dp: Add helper to check DSC1.2 for HDMI2.1 DFP

["Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com>]

On 8/23/2022 4:32 PM, Jani Nikula wrote:
> On Mon, 22 Aug 2022, Ankit Nautiyal <ankit.k.nautiyal@intel.com> wrote:
>> Add helper function to check if Downstream HDMI 2.1 sink supports
>> DSC1.2.
> If we do this, are we going to add helpers for all the details in
> display_info, when there's no conversions being done? I think the answer
> should be "no".
>
> i.e. why do we really need this?

Hmm well initially I was checking both the dsc_max_frl rate and dsc 
version, but dropped the dsc_max_frl rate check later.

(need another patch series to fix DSC parsing from HFVSDB: 
https://patchwork.freedesktop.org/series/107146/ )

In current form, this function does seem unnecessary,  I will drop this 
patch from the series.

Thanks & Regards,

Ankit


> BR,
> Jani.
>
>> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
>> ---
>>   drivers/gpu/drm/i915/display/intel_dp.c | 13 +++++++++++--
>>   1 file changed, 11 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
>> index 32292c0be2bd..fdf82373a22d 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>> @@ -118,6 +118,15 @@ bool intel_dp_is_edp(struct intel_dp *intel_dp)
>>   static void intel_dp_unset_edid(struct intel_dp *intel_dp);
>>   static int intel_dp_dsc_compute_bpp(struct intel_dp *intel_dp, u8 dsc_max_bpc);
>>   
>> +static bool
>> +is_dfp_hdmi_sink_dsc_1_2(struct intel_dp *intel_dp)
>> +{
>> +	struct intel_connector *intel_connector = intel_dp->attached_connector;
>> +	struct drm_connector *connector = &intel_connector->base;
>> +
>> +	return connector->display_info.hdmi.dsc_cap.v_1p2;
>> +}
>> +
>>   /* Is link rate UHBR and thus 128b/132b? */
>>   bool intel_dp_is_uhbr(const struct intel_crtc_state *crtc_state)
>>   {
>> @@ -2393,7 +2402,7 @@ static int intel_dp_hdmi_sink_max_frl(struct intel_dp *intel_dp)
>>   	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) {
>> +	if (is_dfp_hdmi_sink_dsc_1_2(intel_dp)) {
>>   		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;
>>   		if (max_dsc_lanes && dsc_rate_per_lane)
>> @@ -2605,7 +2614,7 @@ intel_dp_pcon_dsc_configure(struct intel_dp *intel_dp,
>>   	if (!intel_connector)
>>   		return;
>>   	connector = &intel_connector->base;
>> -	hdmi_is_dsc_1_2 = connector->display_info.hdmi.dsc_cap.v_1p2;
>> +	hdmi_is_dsc_1_2 = is_dfp_hdmi_sink_dsc_1_2(intel_dp);
>>   
>>   	if (!drm_dp_pcon_enc_is_dsc_1_2(intel_dp->pcon_dsc_dpcd) ||
>>   	    !hdmi_is_dsc_1_2)