Modesetting (amdgpudrmfb) artifacts on RAVEN APU

[KARBOWSKI Piotr]

On 2018-03-07 17:48, KARBOWSKI Piotr wrote:
> On 2018-03-07 17:14, Harry Wentland wrote:
>> Pushed a drm-fixes-4.16 branch (based on Alex's) to my FDO repo 
>> athttps://cgit.freedesktop.org/~hwentland/linux/  but I don't have a 
>> Raven system setup to test this at the moment.
>>
>> Tom, or Piotr, would you be able to check that the fix works as 
>> intended on that branch?
> 
> Tested that branch, confirmed that the VGA patch is there but I got the 
> original result of broken video. Rebooted few times. It seems that my 
> issue was not the VGA turnover afterall. I will re-test it with vanilla 
> amd-staging-drm-next of git://people.freedesktop.org/~agd5f/linux 
> without the VGA patch and update you.

I re-tested original tree of git://people.freedesktop.org/~agd5f/linux 
on branch amd-staging-drm-next and got the 'double screen' glitches, 
then I applied the patch Tom sent me as the very first response to this 
thread and then it indeed fixed it. So the VGA takeover patch is needed 
it, it seems.

I triple checked and build the images and the drm-fixes-4.16 of 
git://people.freedesktop.org/~hwentland/linux does not fix the problem 
for me.

So far only amd-staging-drm-next with 
0001-drm-amd-display-Fix-takeover-from-VGA-mode.patch does the trick. 
One thing worth note is that the amd-staging-drm-next goes as `rc1` 
where yours fork Harry appears to be rc3, no idea if it's related or not.

-- Piotr.