[PATCH v1 2/2] drm: Clear the fence pointer when writeback job signaled

[Lowry Li (Arm Technology China)]

Hi Brian,

On Wed, Jul 31, 2019 at 09:20:04PM +0800, Brian Starkey wrote:
> Hi Lowry,
> 
> Thanks for this cleanup.
> 
> On Wed, Jul 31, 2019 at 11:04:45AM +0000, Lowry Li (Arm Technology China) wrote:
> > During it signals the completion of a writeback job, after releasing
> > the out_fence, we'd clear the pointer.
> > 
> > Check if fence left over in drm_writeback_cleanup_job(), release it.
> > 
> > Signed-off-by: Lowry Li (Arm Technology China) <lowry.li at arm.com>
> > ---
> >  drivers/gpu/drm/drm_writeback.c | 23 +++++++++++++++--------
> >  1 file changed, 15 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
> > index ff138b6..43d9e3b 100644
> > --- a/drivers/gpu/drm/drm_writeback.c
> > +++ b/drivers/gpu/drm/drm_writeback.c
> > @@ -324,6 +324,9 @@ void drm_writeback_cleanup_job(struct drm_writeback_job *job)
> >  	if (job->fb)
> >  		drm_framebuffer_put(job->fb);
> >  
> > +	if (job->out_fence)
> 
> I'm thinking it might be a good idea to signal the fence with an error
> here, if it's not already signaled. Otherwise, if there's someone
> waiting (which there shouldn't be), they're going to be waiting a very
> long time :-)
> 
> Thanks,
> -Brian
> 
Here it happened at atomic_check failed and test only commit. For both
cases, the commit has been dropped and it's only a clean up. So here better
not be treated as an error case:)

Since for userspace, it should have been failed or a test only case, so
writebace fence should not be signaled.

Best regards,
Lowry
> > +		dma_fence_put(job->out_fence);
> > +
> >  	kfree(job);
> >  }

-- 
Regards,
Lowry