[Nouveau] [PATCH] nouveau: explicitly wait on the fence in nouveau_bo_move_m2mf

[Karol Herbst]

On Tue, Nov 1, 2022 at 7:45 AM Computer Enthusiastic
<computer.enthusiastic at gmail.com> wrote:
>
> Hello,
>
> Il giorno ven 19 ago 2022 alle ore 22:09 Karol Herbst
> <kherbst at redhat.com> ha scritto:
> >
> > It is a bit unlcear to us why that's helping, but it does and unbreaks
> > suspend/resume on a lot of GPUs without any known drawbacks.
> >
> > Cc: stable at vger.kernel.org # v5.15+
> > Closes: https://gitlab.freedesktop.org/drm/nouveau/-/issues/156
> > Signed-off-by: Karol Herbst <kherbst at redhat.com>
> > ---
> >  drivers/gpu/drm/nouveau/nouveau_bo.c | 9 +++++++++
> >  1 file changed, 9 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
> > index 35bb0bb3fe61..126b3c6e12f9 100644
> > --- a/drivers/gpu/drm/nouveau/nouveau_bo.c
> > +++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
> > @@ -822,6 +822,15 @@ nouveau_bo_move_m2mf(struct ttm_buffer_object *bo, int evict,
> >                 if (ret == 0) {
> >                         ret = nouveau_fence_new(chan, false, &fence);
> >                         if (ret == 0) {
> > +                               /* TODO: figure out a better solution here
> > +                                *
> > +                                * wait on the fence here explicitly as going through
> > +                                * ttm_bo_move_accel_cleanup somehow doesn't seem to do it.
> > +                                *
> > +                                * Without this the operation can timeout and we'll fallback to a
> > +                                * software copy, which might take several minutes to finish.
> > +                                */
> > +                               nouveau_fence_wait(fence, false, false);
> >                                 ret = ttm_bo_move_accel_cleanup(bo,
> >                                                                 &fence->base,
> >                                                                 evict, false,
> > --
> > 2.37.1
> >
>
> Do you think it could be possible to make the patch land in kernel
> 5.10.x in the near future ?
>
> Is there something I can do to help it to happen ?
>

you can send it out to the stable mailing list and I ack it there. I
just totally forgot about it, sorry.

> Thanks.
>