Modesetting (amdgpudrmfb) artifacts on RAVEN APU

[KARBOWSKI Piotr]

On 2018-03-07 20:31, KARBOWSKI Piotr wrote:
> On 2018-03-07 20:12, Harry Wentland wrote:
>> Thanks for testing.
>>
>> What do you mean with broken video? I tried going back in the email 
>> thread but I'm not 100% clear what you mean by this.
>>
>> BTW, drm-fixes-4.16 are fixes we intend to get into the 4.16 upstream 
>> kernel. amd-staging-drm-next is our development tree and quite a bit 
>> farther ahead in development. I'm trying to find fixes to backmerge to 
>> 4.16 to make everyone happy when it releases.
> 
> Like on those screenshots
> 
> 
>      https://i.imgur.com/qnDOKY7.jpg
>      https://i.imgur.com/XH42zit.jpg
> 
> To describe it better, lets split the screen into 4 segments
> 
> +-----+-----+
> |  A  |  B  |
> +-----+-----+
> |  C  |  D  |
> +-----+-----+
> 
> The screen resolution kicks in as it should, 1080p, then A displays 
> proper part of screen, around 25%, then B contain a copy of what A 
> displays, so the same 25% of top-left part of screen, then C and D 
> remain black, if I scroll the screen a bit, C and D an get a bold 
> vertical line of whatever color was on screen, if I had a white/gray 
> font, it will be it, if there was some blue text, it will be blue until 
> I scroll a bit more.
> 
> 
> drm-fixes-4.16 yield the same effect as amd-staging-drm-next without 
> 0001-drm-amd-display-Fix-takeover-from-VGA-mode.patch, but it seems that 
> htis patch is already in drm-fixes-4.16 so I am confused.

I was not correct.

The drm-fixes-4.16 is a bit better It fixes half of my issue! So with 
this handy ascii art of mine

   +-----+-----+
   |  A  |  B  |
   +-----+-----+
   |  C  |  D  |
   +-----+-----+

A and C works, so I have full termianl on left side. but B remains copy 
of A and D either is black of have the fancy line.

I compared manually the patch that did worked for me and it seems it was 
not fully applied, the .h and .c does not look the same. Perhaps that's 
the source here.

-- Piotr.