Nouveau - Jan 2023 - [PATCH] nouveau: explicitly wait on the fence in nouveau_bo_move_m2mf

Hello Karol,

Il giorno mar 1 nov 2022 alle ore 11:46 Karol Herbst
<kherbst at redhat.com> ha scritto:
>
> 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.
> >
As you suggested, I sent a request to a request to linux-kernel [1],
but it was not acknowledged.

What else can I do to help the patch land in the 5.10.x kernel in the future ?

Thanks and happy Christmas.

[1] https://marc.info/?l=linux-kernel&m=166883482714930&w=2

Hello,

The patch "[Nouveau] [PATCH] nouveau: explicitly wait on the fence in 
nouveau_bo_move_m2mf" [1] was marked for kernels v5.15+ and it was 
merged upstream.

The same patch [1] works with kernel 5.10.y, but it is not been merged 
upstream so far.

According to Karol Herbst suggestion [2], I'm sending this message to 
ask for merging it into 5.10 kernel.

Thanks in advance.

---
[1] 
https://lore.kernel.org/nouveau/20220819200928.401416-1-kherbst at redhat.com/

[2] 
https://lore.kernel.org/nouveau/CACO55tv0jO2TmuWcwFiAUQB-__DZVwhv7WNN9MfgMXV053gknw
at mail.gmail.com/