On Thu, May 8, 2025 at 7:08 PM Lucas Stach <l.st...@pengutronix.de> wrote:
>
> Am Donnerstag, dem 08.05.2025 um 16:56 +0200 schrieb Tomeu Vizoso:
> > We should be comparing the last submitted sequence number with that of
> > the address space we may be switching to.
> >
> This isn't the relevant change here though: if we switch the address
> space, the comparison is moot, as we do a full flush on AS switch
> anyway. The relevant change is that with the old code we would record
> the flush sequence of the AS we switch away from as the current flush
> sequence, so we might miss a necessary flush on the next submission if
> that one doesn't require a AS switch, but would only flush based on
> sequence mismatch.
Ah, you are right.
> Mind if I rewrite the commit message along those lines while applying?
Sure, no problem.
Thanks,
Tomeu
> Regards,
> Lucas
>
> > Fixes: 27b67278e007 ("drm/etnaviv: rework MMU handling")
> > Signed-off-by: Tomeu Vizoso <to...@tomeuvizoso.net>
> > ---
> > drivers/gpu/drm/etnaviv/etnaviv_buffer.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/etnaviv/etnaviv_buffer.c
> > b/drivers/gpu/drm/etnaviv/etnaviv_buffer.c
> > index b13a17276d07..88385dc3b30d 100644
> > --- a/drivers/gpu/drm/etnaviv/etnaviv_buffer.c
> > +++ b/drivers/gpu/drm/etnaviv/etnaviv_buffer.c
> > @@ -347,7 +347,7 @@ void etnaviv_buffer_queue(struct etnaviv_gpu *gpu, u32
> > exec_state,
> > u32 link_target, link_dwords;
> > bool switch_context = gpu->exec_state != exec_state;
> > bool switch_mmu_context = gpu->mmu_context != mmu_context;
> > - unsigned int new_flush_seq = READ_ONCE(gpu->mmu_context->flush_seq);
> > + unsigned int new_flush_seq = READ_ONCE(mmu_context->flush_seq);
> > bool need_flush = switch_mmu_context || gpu->flush_seq !=
> > new_flush_seq;
> > bool has_blt = !!(gpu->identity.minor_features5 &
> > chipMinorFeatures5_BLT_ENGINE);
>
