[PATCH 2/9] drm/xe: Stop the TLB fence timer on driver teardown

[Matthew Brost]

On Wed, Aug 13, 2025 at 02:19:20PM -0700, Matthew Brost wrote:
> On Wed, Aug 13, 2025 at 07:47:59PM +0000, stuartsummers wrote:
> > There is a small window of time during the driver teardown where
> > the TLB invalidation fence->gt is set to NULL but an invalidation
> > worker is still alive. This won't cause an issue currently because
> > the tlb_invalidation structure itself is still present. However as
> > part of a future refactor, we are looking to split that structure
> > out. To be safe, go ahead and cancel any outstanding TLB invalidation
> > fence worker thread on _fini() since at that time we are already
> > tearing down the driverworker thread on _fini() since at that time we
> > are already tearing down the driver and don't need to continue
> > monitoring this.
> > 
> > Signed-off-by: stuartsummers <stuart.summers at intel.com>
> > ---
> >  drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c b/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c
> > index 75854b963d66..08e882433b13 100644
> > --- a/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c
> > +++ b/drivers/gpu/drm/xe/xe_gt_tlb_invalidation.c
> > @@ -44,6 +44,8 @@ static void xe_gt_tlb_invalidation_fence_fini(struct xe_gt_tlb_invalidation_fenc
> >  	if (WARN_ON_ONCE(!fence->gt))
> >  		return;
> >  
> > +	cancel_delayed_work(&fence->gt->tlb_invalidation.fence_tdr);
> 
> I think cancel_delayed_work_sync is what we want here.
> 
> Matt

Wait, I was thinking this was the fini handler called from drmm.

Would it work add drmm handler for driver teardown that
calls cancel_delayed_work_sync and signals any pending TLB invalidation
fences?

Matt

> 
> > +
> >  	xe_pm_runtime_put(gt_to_xe(fence->gt));
> >  	fence->gt = NULL; /* fini() should be called once */
> >  }
> > -- 
> > 2.34.1
> >