[Nouveau] Should I expect nouveau on 4.6 to work on a GM206?

[Andy Lutomirski]

On Sun, May 29, 2016 at 12:27 PM, Andy Lutomirski <luto at kernel.org> wrote:
> On Sun, May 29, 2016 at 12:22 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>> On Sun, May 29, 2016 at 3:07 PM, Andy Lutomirski <luto at kernel.org> wrote:
>>> On Sat, May 28, 2016 at 5:48 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>>>> Do you have mesa 11.2 or later? GM20x support was only added in mesa 11.2.
>>>>
>>>
>>> I just upgraded to 11.2.  I'm getting errors like this in the log:
>>>
>>> [ 5383.723240] nouveau 0000:09:00.0: fifo: read fault at 0000011000
>>> engine 07 [PBDMA0] client 06 [HOST] reason 00 [PDE] on channel -1
>>> [007f9ed000 unknown]
>>> [ 5398.722676] nouveau 0000:09:00.0: systemd-logind[30778]: failed to
>>> idle channel 2 [systemd-logind[30778]]
>>> [ 5413.722853] nouveau 0000:09:00.0: systemd-logind[30778]: failed to
>>> idle channel 2 [systemd-logind[30778]]
>>>
>>> and the display output in general is unreliable enough that I'm having
>>> trouble telling whether the performance is remotely reasonable.
>>
>> If you're having trouble telling, that means it's not :) The error you
>> pasted is quite odd. Was there anything in the log before those
>> messages? If there's no channel associated, that means that it's the
>> background copying between vram and sysmem? Not sure.
>
> Don't get too excited yet.  In the process of upgrading mesa, I
> managed to boot 4.5 without noticing.  I'll post back later today with
> actual valid test results.
>

I replaced the monitor (turns out that my monitor had a known DP
problem), and now the screen lights up reliably.  I still get
occasional log lines like this:

[Jun26 09:25] nouveau 0000:09:00.0: fifo: FB_FLUSH_TIMEOUT
[Jun26 09:30] nouveau 0000:09:00.0: fifo: FB_FLUSH_TIMEOUT
[Jun26 09:32] nouveau 0000:09:00.0: fifo: CHSW_ERROR 00000004
[  +0.000162] nouveau 0000:09:00.0: fifo: CHSW_ERROR 00000005
[Jun26 09:46] nouveau 0000:09:00.0: disp: outp 04:0006:0f44: link
training failed
[  +0.107894] nouveau 0000:09:00.0: disp: outp 04:0006:0f44: link
training failed

but they aren't causing an obvious problem.

>>
>> Note that with maxwell we have yet to add EXA support to
>> xf86-video-nouveau, so you're ending up with GLAMOR (and Ben and I
>> disagree on whether EXA support should be added in the first place).
>> There was also an issue that glamor was hitting with nouveau which
>> appears to have dissipated, either due to a change in nouveau or a
>> change in glamor. So you might consider upgrading to Xorg 1.18.3 (as
>> glamor is part of X).

I do have a serious performance issue, though: when I scroll in
Firefox (default configuration), the whole system drops to ~1fps or
less and, if I scroll enough (even putting the mouse over a simple
page like start.fedoraproject.org and flicking the wheel up and down a
few times), the entire desktop will become unusable for several
seconds.  I seem to have this problem under X and under Wayland.

For better or for worse, forcing Firefox's layers acceleration on
fixes the problem and scrolling is fast.

I have no idea whether this is an X problem, a gnome-shell problem, a
mesa problem, a kernel problem, or something else.