[Intel-xe] [PATCH 2/3] drm/vblank: Warn when silently cancelling vblank works

[Ville Syrjälä]

On Wed, Sep 20, 2023 at 03:55:28PM -0400, Lyude Paul wrote:
> Good point!
> 
> Reviewed-by: Lyude Paul <lyude at redhat.com>

Thanks. Pushed to drm-misc-next.

> 
> On Wed, 2023-09-20 at 17:03 +0300, Ville Syrjala wrote:
> > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > 
> > Silently cancelling vblank works is a bit rude, especially
> > if said works do any resource management (eg. free memory).
> > WARN if we ever hit this.
> > 
> > TODO: Maybe drm_crtc_vblank_off() should wait for any
> > pending work to reach its target vblank before actually
> > doing anything drastic?
> > 
> > Cc: Lyude Paul <lyude at redhat.com>
> > Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > ---
> >  drivers/gpu/drm/drm_vblank_work.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/drm_vblank_work.c b/drivers/gpu/drm/drm_vblank_work.c
> > index bd481fdd6b87..43cd5c0f4f6f 100644
> > --- a/drivers/gpu/drm/drm_vblank_work.c
> > +++ b/drivers/gpu/drm/drm_vblank_work.c
> > @@ -73,6 +73,9 @@ void drm_vblank_cancel_pending_works(struct drm_vblank_crtc *vblank)
> >  
> >  	assert_spin_locked(&vblank->dev->event_lock);
> >  
> > +	drm_WARN_ONCE(vblank->dev, !list_empty(&vblank->pending_work),
> > +		      "Cancelling pending vblank works!\n");
> > +
> >  	list_for_each_entry_safe(work, next, &vblank->pending_work, node) {
> >  		list_del_init(&work->node);
> >  		drm_vblank_put(vblank->dev, vblank->pipe);
> 
> -- 
> Cheers,
>  Lyude Paul (she/her)
>  Software Engineer at Red Hat

-- 
Ville Syrjälä
Intel