[PATCH] drm/syncobj: ensure progress for syncobj queries

[Chia-I Wu]

On Tue, Oct 22, 2024 at 3:30 AM Boris Brezillon
<boris.brezillon at collabora.com> wrote:
>
> On Thu, 17 Oct 2024 09:20:53 -0700
> Chia-I Wu <olvaffe at gmail.com> wrote:
>
> > Userspace might poll a syncobj with the query ioctl.  Call
> > dma_fence_enable_sw_signaling to ensure dma_fence_is_signaled returns
> > true in finite time.
> >
> > ---
> >
> > panvk hits this issue when timeline semaphore is enabled.  It uses the
> > transfer ioctl to propagate fences.  dma_fence_unwrap_merge converts the
> > dma_fence_chain to a dma_fence_array.  dma_fence_array_signaled never
> > return true unless signaling is enabled.
>
> Looks like a bugfix to me. Should we add Fixes+Cc-stable tags so it
> gets backported to stable branches.
Thanks.  v2 sent with the Fixes tag.  I did not add Cc-stable because
I was told it was the maintainers' decision last time.