[PATCH] amd/dc/dce100: On dce100, set clocks to 0 on suspend

[Harry Wentland]

On 2018-07-12 10:29 AM, Francis, David wrote:
> Upon closer inspection, this does not match any FDO bug.  The FDO bug I thought this was related to was fixed by Michel Danzer, and this fixes an entirely separate issue.
> 

If I remember right we have a regression change for this. We should add that with the Fixes tag like so

Fixes: 308425ff39dc ("drm/amd/display: redesign dce/dcn clock voltage update request")

Looks like it's not in any kernel tag yet, so no need to add stable like I previously thought.

Harry

> ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
> *From:* Michel Dänzer <michel at daenzer.net>
> *Sent:* July 12, 2018 10:18:34 AM
> *To:* Wentland, Harry; Francis, David; amd-gfx at lists.freedesktop.org
> *Subject:* Re: [PATCH] amd/dc/dce100: On dce100, set clocks to 0 on suspend
>  
> On 2018-07-12 04:13 PM, Harry Wentland wrote:
>> On 2018-07-12 10:07 AM, David Francis wrote:
>>> [Why]
>>> When a dce100 asic was suspended, the clocks were not set to 0.
>>> Upon resume, the new clock was compared to the existing clock,
>>> they were found to be the same, and so the clock was not set.
>>> This resulted in a pernicious blackscreen.
>>>
>>> [How]
>>> In atomic commit, check to see if there are any active pipes.
>>> If no, set clocks to 0
>>>
>> 
>> Please add Fixes: tag with link to freedesktop bugzilla bug that this fixes.
> 
> That would be
> 
> Bugzilla: https://...
> 
> (the Fixes tag is for referencing another commit which is fixed by this one)
> 
> 
> -- 
> Earthling Michel Dänzer               |               http://www.amd.com
> Libre software enthusiast             |             Mesa and X developer