[Nouveau] [PATCH/TESTING(all hw)/DISCUSSION] FIFO (minor) create and (major) destroy instabilities on nv50+

[Maarten Maathuis]

Please do report your successes, and not only failures.

On Sat, Jan 2, 2010 at 4:36 PM, Maarten Maathuis <madman2003 at gmail.com> wrote:
> Many people using nv50+ hardware are aware of gpu lockups when a fifo
> closes under certain conditions. Based on a mmio-trace and some trail
> and error testing i've come up with a patch that improves the
> situation on my NV96.
>
> This patch needs testing on NV50+ hardware and regression testing on
> older hardware, since i did change some of the common codepaths. This
> is very much a work in progress, and if you have anything to
> add/correct, please share it.
>
> I've also attached a 2 test apps, once is bitscan-fail from mwk, use
> it like ./bitscan-fail 0x200 to trigger PGRAPH errors. A modified
> version only emits NOPs (method 0x100) and represents the no error
> situation.
>
> For me, i can run the NOP program in loops of 10000 iterations with no
> problems (i've done so several times), the bitscan-fail survives 10000
> iterations sometimes, but can also fail after a few thousand. In
> comparison, a single run of bitscan-fail could cause a gpu lockup for
> me in the past.
>
> Please try the gallium driver, the test apps, suspend to ram. Suspend
> to ram isn't 100% reliable yet for me (this was always the case after
> strange experiments/hammering/etc), but should not regress. This goes
> for older hw as well, whatever worked should still work, but i
> wouldn't expect serious improvements there.
>
> As always, feedback is appreciated, especially since this is a touchy subject.
>
> Maarten.
>