[+Alex +Christian]

On 5/21/26 09:09, Michel Dänzer wrote:
> On 5/20/26 17:54, Pei-Hsin Yang wrote:
>>
>>> Tested with 3 HDMI sinks with different FreeSync/HDMI VRR capabilities.  I 
>>> saw one case that a FreeSync sink (Dell S2721HS) with E6h VCP code 
>>> supported was detected as FreeSync capable at beginning but identified as 
>>> not FreeSync capable later – after do_mccs is changed from true to false.
>>
>>>> And that doesn't happen without my patch applied?
>>
>> There are other issues without your patch applied.   One issue is that if a 
>> FreeSync capable sink with MCCS VCP Code = 0 (mostly are TVs), it will be 
>> detected as not FreeSync supported and VRR will be disabled.
> 
> That sounds similar to 
> https://gitlab.freedesktop.org/drm/amd/-/work_items/5286 .
>
> I was wondering if the specific issue you described above with Dell S2721HS 
> is reproducible without my patch though, in which case it might be a separate 
> regression (and wouldn't speak against merging my patch).
> 
> 
>>>> TBH I don't really want to be fixing the regression I hit, I'd prefer the 
>>>> AMD display team to handle it.
>>
>> Yes, agreed.  As FreeSync MCCS support has immediate impacts to Valve's 
>> Steam devices, I will work with AMD display team to handle it.   HDMI 2.1 
>> VRR and VTEM packet sending support need to be included as well.
> 
> Note that some kind of short-term solution is needed for the regression(s) in 
> 7.1-rc.

Yeah, that would be good. Makes me wonder how the rough plan to realize
this looks like? Sounds like Michael's patch[1] that was discussed here
is not a good option? Reminder, Linus ideally wants known regression
fixed by -rc6, which is why I'm asking.

Ciao, Thorsten

[1]
https://lore.kernel.org/amd-gfx/[email protected]/

Reply via email to