Regression with kernel 4.20 on armhf

[Luís Mendes]

Reply in between.

On Fri, Jan 4, 2019 at 4:22 PM Michel Dänzer <michel at daenzer.net> wrote:
>
> On 2019-01-04 4:32 p.m., Luís Mendes wrote:
> > Hi Alex, Christian,
> >
> > I've tested amd-staging-drm-next at commit
> > 9698024e8a191481321574bec1fe886bbce797cf - drm/amdgpu: Cleanup 2
> > compiler warnings,
> > and now RX 550 Polaris 12 still hangs in ring gfx with XOrg, but a gpu
> > recovery is now performed and works, except that VRAM contents are
> > lost and screen image becomes corrupted.
>
> This is because OpenGL contexts become unusable when a full GPU reset is
> performed. Making it possible to fully recover from this without
> restarting Xorg (which uses OpenGL via glamor) or at least the
> compositor / other apps using OpenGL would be tricky and require a lot
> of effort, so I wouldn't bet on it ever happening I'm afraid.

Makes sense.

>
>
> > Maybe this is not a driver issue, but rather a mesa or XOrg issue,
> > since something is sent to the compute/gfx unit that causes the GPU to
> > hang, so it is not only timing sensitive, but is mainly because of
> > wrong openGL commands, that drive the GPU into an invalid state
>
> In that case, the problem would be expected to happen the same way on
> x86 as well. There seems to be some kind of platform specific aspect
> affecting it.

It is quite possible this also affects x86. I just haven't tried
running Ubuntu MATE 18.04 on x86.

>
>
> --
> Earthling Michel Dänzer               |               http://www.amd.com
> Libre software enthusiast             |             Mesa and X developer