Re: [Intel-gfx] [PATCH] drm/i915/dsc: Source supports DSC from DISPLAY_VER >= 11

[Swati Sharma <swati2.sharma@intel.com>]

Hi Matt,

Yes. Though h/w supports DSC from gen10, DSC is enabled from gen11+ from 
driver.
We can see "has_dsc" flag enabled in gen11+.
#define GEN11_FEATURES \
 >-------.__runtime.has_dsc = 1, \

Also, in the driver intel_dsc_source_support(), it is
if (DISPLAY_VER(i915) >= 11 && cpu_transcoder != TRANSCODER_A)
                 return true;
So, we should align DISPLAY_VER check according to DSC enablement
from driver.

On 02-Nov-22 2:50 AM, Matt Roper wrote:
> On Tue, Nov 01, 2022 at 01:29:27PM +0530, Swati Sharma wrote:
>> i915 driver supports DSC from DISPLAY_VER >= 11. Fix it.
> 
> Bspec 19713 indicates that GLK (i.e., our only display version 10
> platform) does support DSC.  Are you saying that there's other GLK
> enablement missing in the driver right now that prevents DSC from
> working?
> 
> 
> Matt
> 
>>
>> Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
>> ---
>>   drivers/gpu/drm/i915/display/intel_dp.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
>> index 7400d6b4c587..02e64f0284d8 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>> @@ -1012,7 +1012,7 @@ intel_dp_mode_valid(struct drm_connector *_connector,
>>   	 * Output bpp is stored in 6.4 format so right shift by 4 to get the
>>   	 * integer value since we support only integer values of bpp.
>>   	 */
>> -	if (DISPLAY_VER(dev_priv) >= 10 &&
>> +	if (DISPLAY_VER(dev_priv) >= 11 &&
>>   	    drm_dp_sink_supports_dsc(intel_dp->dsc_dpcd)) {
>>   		/*
>>   		 * TBD pass the connector BPC,
>> @@ -2906,7 +2906,7 @@ intel_edp_init_dpcd(struct intel_dp *intel_dp)
>>   	intel_dp_set_max_sink_lane_count(intel_dp);
>>   
>>   	/* Read the eDP DSC DPCD registers */
>> -	if (DISPLAY_VER(dev_priv) >= 10)
>> +	if (DISPLAY_VER(dev_priv) >= 11)
>>   		intel_dp_get_dsc_sink_cap(intel_dp);
>>   
>>   	/*
>> -- 
>> 2.25.1
>>
> 

-- 
~Swati Sharma