Re: [PATCH 5/7] drm/i915/dp: Refactor pipe_bpp limits with dsc

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

On 10/17/2024 5:50 PM, Imre Deak wrote:
> On Thu, Oct 03, 2024 at 04:13:41PM +0530, Ankit Nautiyal wrote:
>> With DSC there are additional limits for pipe_bpp. Currently these are
>> scattered in different places.
>> Instead set the limits->pipe.max/min_bpp in one place and use them
>> wherever required.
>>
>> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
>> ---
>>   drivers/gpu/drm/i915/display/intel_dp.c | 43 ++++++++++---------------
>>   1 file changed, 17 insertions(+), 26 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
>> index 46f3b680afe9..55ee438a4fec 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>> @@ -2166,21 +2166,11 @@ int intel_dp_dsc_min_src_input_bpc(struct intel_display *display)
>>   }
>>   
>>   static
>> -bool is_dsc_pipe_bpp_sufficient(struct drm_i915_private *i915,
>> -				struct link_config_limits *limits,
>> +bool is_dsc_pipe_bpp_sufficient(struct link_config_limits *limits,
>>   				int pipe_bpp)
>>   {
>> -	struct intel_display *display = to_intel_display(&i915->drm);
>> -	int dsc_max_bpc, dsc_min_bpc, dsc_max_pipe_bpp, dsc_min_pipe_bpp;
>> -
>> -	dsc_max_bpc = intel_dp_dsc_max_src_input_bpc(display);
>> -	dsc_min_bpc = intel_dp_dsc_min_src_input_bpc(display);
>> -
>> -	dsc_max_pipe_bpp = min(dsc_max_bpc * 3, limits->pipe.max_bpp);
>> -	dsc_min_pipe_bpp = max(dsc_min_bpc * 3, limits->pipe.min_bpp);
>> -
>> -	return pipe_bpp >= dsc_min_pipe_bpp &&
>> -	       pipe_bpp <= dsc_max_pipe_bpp;
>> +	return pipe_bpp >= limits->pipe.min_bpp &&
>> +	       pipe_bpp <= limits->pipe.max_bpp;
>>   }
>>   
>>   static
>> @@ -2195,7 +2185,7 @@ int intel_dp_force_dsc_pipe_bpp(struct intel_dp *intel_dp,
>>   
>>   	forced_bpp = intel_dp->force_dsc_bpc * 3;
>>   
>> -	if (is_dsc_pipe_bpp_sufficient(i915, limits, forced_bpp)) {
>> +	if (is_dsc_pipe_bpp_sufficient(limits, forced_bpp)) {
>>   		drm_dbg_kms(&i915->drm, "Input DSC BPC forced to %d\n", intel_dp->force_dsc_bpc);
>>   		return forced_bpp;
>>   	}
>> @@ -2212,11 +2202,10 @@ static int intel_dp_dsc_compute_pipe_bpp(struct intel_dp *intel_dp,
>>   					 struct link_config_limits *limits,
>>   					 int timeslots)
>>   {
>> -	struct intel_display *display = to_intel_display(intel_dp);
>>   	const struct intel_connector *connector =
>>   		to_intel_connector(conn_state->connector);
>> -	int dsc_max_bpc, dsc_max_bpp;
>> -	int dsc_min_bpc, dsc_min_bpp;
>> +	int dsc_max_bpp;
>> +	int dsc_min_bpp;
>>   	u8 dsc_bpc[3] = {};
>>   	int forced_bpp, pipe_bpp;
>>   	int num_bpc, i, ret;
>> @@ -2232,14 +2221,8 @@ static int intel_dp_dsc_compute_pipe_bpp(struct intel_dp *intel_dp,
>>   		}
>>   	}
>>   
>> -	dsc_max_bpc = intel_dp_dsc_max_src_input_bpc(display);
>> -	if (!dsc_max_bpc)
>> -		return -EINVAL;
>> -
>> -	dsc_max_bpp = min(dsc_max_bpc * 3, limits->pipe.max_bpp);
>> -
>> -	dsc_min_bpc = intel_dp_dsc_min_src_input_bpc(display);
>> -	dsc_min_bpp = max(dsc_min_bpc * 3, limits->pipe.min_bpp);
>> +	dsc_max_bpp = limits->pipe.max_bpp;
>> +	dsc_min_bpp = limits->pipe.min_bpp;
>>   
>>   	/*
>>   	 * Get the maximum DSC bpc that will be supported by any valid
>> @@ -2284,7 +2267,7 @@ static int intel_edp_dsc_compute_pipe_bpp(struct intel_dp *intel_dp,
>>   
>>   		/* For eDP use max bpp that can be supported with DSC. */
>>   		pipe_bpp = intel_dp_dsc_compute_max_bpp(connector, max_bpc);
>> -		if (!is_dsc_pipe_bpp_sufficient(i915, limits, pipe_bpp)) {
>> +		if (!is_dsc_pipe_bpp_sufficient(limits, pipe_bpp)) {
>>   			drm_dbg_kms(&i915->drm,
>>   				    "Computed BPC is not in DSC BPC limits\n");
>>   			return -EINVAL;
>> @@ -2502,6 +2485,14 @@ intel_dp_compute_config_limits(struct intel_dp *intel_dp,
>>   	limits->pipe.min_bpp = intel_dp_min_bpp(crtc_state->output_format);
>>   	limits->pipe.max_bpp = intel_dp_max_bpp(intel_dp, crtc_state,
>>   						     respect_downstream_limits);
>> +	if (dsc) {
>> +		struct intel_display *display = to_intel_display(intel_dp);
>> +		int dsc_min_bpc = intel_dp_dsc_min_src_input_bpc(display);
>> +		int dsc_max_bpc = intel_dp_dsc_max_src_input_bpc(display);
>> +
>> +		limits->pipe.max_bpp = min(limits->pipe.max_bpp, dsc_max_bpc * 3);
>> +		limits->pipe.min_bpp = max(limits->pipe.min_bpp, dsc_min_bpc * 3);
>> +	}
> Then intel_dp_mst_compute_config_limits() would also need to do the
> same.

The function mst_stream_compute_config_limits() is calling this 
function, so that should be covered.

Regards,

Ankit


>
>>   
>>   	if (intel_dp->use_max_params) {
>>   		/*
>> -- 
>> 2.45.2
>>