[PATCH v2 2/2] dma-buf/sw_sync: force signal all unsignaled fences on dying timeline

[Chris Wilson]

Quoting Gustavo Padovan (2017-09-08 14:03:00)
> Hi Chris,
> 
> 2017-09-07 Chris Wilson <chris at chris-wilson.co.uk>:
> 
> > Quoting Gustavo Padovan (2017-09-07 20:02:46)
> > > From: Dominik Behr <dbehr at chromium.org>
> > > 
> > > To avoid hanging userspace components that might have been waiting on the
> > > active fences of the destroyed timeline we need to signal with error all
> > > remaining fences on such timeline.
> > > 
> > > This restore the default behaviour of the Android sw_sync framework, which
> > > Android still relies on. It was broken on the dma fence conversion a few
> > > years ago and never fixed.
> > > 
> > > v2: Do not bother with cleanup do the list (Chris Wilson)
> > > 
> > > Signed-off-by: Dominik Behr <dbehr at chromium.org>
> > > Signed-off-by: Gustavo Padovan <gustavo.padovan at collabora.com>
> > Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
> > 
> > > ---
> > >  drivers/dma-buf/sw_sync.c | 10 ++++++++++
> > >  1 file changed, 10 insertions(+)
> > > 
> > > diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c
> > > index 38cc7389a6c1..f183eef074fd 100644
> > > --- a/drivers/dma-buf/sw_sync.c
> > > +++ b/drivers/dma-buf/sw_sync.c
> > > @@ -321,9 +321,19 @@ static int sw_sync_debugfs_open(struct inode *inode, struct file *file)
> > >  static int sw_sync_debugfs_release(struct inode *inode, struct file *file)
> > >  {
> > >         struct sync_timeline *obj = file->private_data;
> > > +       struct sync_pt *pt, *next;
> > >  
> > >         smp_wmb();
> > >  
> > > +       spin_lock_irq(&obj->lock);
> > 
> > Given the spinlock, that uncommented barrier (what is it paired with?)
> > above is redundant.
> 
> Okay, I'll remove the barrier and push that patch, I assume your r-b
> will comtemplate that as well?

No worries, either as one patch or two, slap my r-b on it.
-Chris