Bug 90873

Created attachment 116321 [details]
xorg

Created attachment 116322 [details]
xorg.conf

(In reply to Tom from comment #0)
> I experience GPU hang while TearFree option is on.

Does it hang when you do anything in particular?

FWIW, this line in dmesg is probably related:

[  141.232226] radeon 0000:01:00.0: bo ffff8804236d3400 va 0x0000001000 conflict with (bo ffff88042a018800 0x0000001000 0x0000001563)

but I'm not sure what would cause that.


> I've tested TearFree when this feature was introduced in git version of
> xf86-video-ati-git and I didn't experience GPU hang back then.

Can you try isolating the xf86-video-ati commit introducing the hang with git bisect?

(In reply to Michel Dänzer from comment #3)
> (In reply to Tom from comment #0)
> > I experience GPU hang while TearFree option is on.
> 
> Does it hang when you do anything in particular?
> 
> FWIW, this line in dmesg is probably related:
> 
> [  141.232226] radeon 0000:01:00.0: bo ffff8804236d3400 va 0x0000001000
> conflict with (bo ffff88042a018800 0x0000001000 0x0000001563)
> 
> but I'm not sure what would cause that.
> 
> 
> > I've tested TearFree when this feature was introduced in git version of
> > xf86-video-ati-git and I didn't experience GPU hang back then.
> 
> Can you try isolating the xf86-video-ati commit introducing the hang with
> git bisect?

I investigated it a bit. When I start lightdm it starts fine. I've created new linux user without any desktop config and it desktop env started also ok. Then I've changed resolution using desktop environment tool and then problem appeared. The same happened when used xrandr.

http://lists.freedesktop.org/archives/dri-devel/2015-June/084514.html fixes the hang for me (not a GPU hang but a kernel hang, because it tries to lock a mutex that's already locked).


> [  141.232226] radeon 0000:01:00.0: bo ffff8804236d3400 va 0x0000001000
> conflict with (bo ffff88042a018800 0x0000001000 0x0000001563)

These still happen, but at least with GNOME it continues working for me somehow. I tried various workarounds for this in the Xorg driver, but I haven't found anything that avoids these. I think the proper solution for these would be for the kernel driver to track GPU VA ranges per GEM handle instead of per BO.

(In reply to Michel Dänzer from comment #5)
> http://lists.freedesktop.org/archives/dri-devel/2015-June/084514.html fixes
> the hang for me (not a GPU hang but a kernel hang, because it tries to lock
> a mutex that's already locked).
> 
> 
> > [  141.232226] radeon 0000:01:00.0: bo ffff8804236d3400 va 0x0000001000
> > conflict with (bo ffff88042a018800 0x0000001000 0x0000001563)
> 
> These still happen, but at least with GNOME it continues working for me
> somehow. I tried various workarounds for this in the Xorg driver, but I
> haven't found anything that avoids these. I think the proper solution for
> these would be for the kernel driver to track GPU VA ranges per GEM handle
> instead of per BO.

The latest patch applied to linux kernel rc8 fixed this issue, thanks.

Resolved in kernel 4.1-rc8