Re: [PATCH v3 1/2] drm/i915/display/dp: Remove UHBR13.5 for icl

[Jani Nikula <jani.nikula@linux.intel.com>]

On Wed, 02 Apr 2025, Jani Nikula <jani.nikula@linux.intel.com> wrote:
> On Wed, 02 Apr 2025, Arun R Murthy <arun.r.murthy@intel.com> wrote:
>> Per Bspec display 14+ has uhbr13.5 Due to the retimer constraint none of
>> the Intel platforms support uhbr13.5.
>
> Those two sentences together make no sense.
>
> The subject makes no sense, because icl never supported UHBR.
>
>> This has been removed for mtl
>> by the commit caf3d748f646 ("drm/i915/dp: Remove support for UHBR13.5")
>> This patch will remove the support for DG2.
>
> "This patch" and "will" are unnecessary fillers. And once a patch is
> committed, "this patch" is meaningless.
>
> Just "Remove ..." is fine.
>
> dg2_max_source_rate() *still* refers to 1350000 as max rate, and that's
> arguably more important than the rates array. And you can just remove
> the entire function because it becomes a constant.

Except of course not, because that would drop UHBR support
completely. You just need to adjust the rate in the function to reflect
reality.

>
> BR,
> Jani.
>
>>
>> v2: Reframed the commit msg (Jani)
>>
>> Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
>> ---
>>  drivers/gpu/drm/i915/display/intel_dp.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
>> index f21f9b441fc2a4e644c69410e6ec6b3d37907478..d7955351dd43ff61ebfd57e5b6a4ba99c1c7a2b2 100644
>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>> @@ -550,7 +550,7 @@ intel_dp_set_source_rates(struct intel_dp *intel_dp)
>>  	};
>>  	static const int icl_rates[] = {
>>  		162000, 216000, 270000, 324000, 432000, 540000, 648000, 810000,
>> -		1000000, 1350000,
>> +		1000000,
>>  	};
>>  	static const int bxt_rates[] = {
>>  		162000, 216000, 243000, 270000, 324000, 432000, 540000

-- 
Jani Nikula, Intel