[Intel-gfx] [PATCH] drm/i915/display: Warn if the FBC is still writing to stolen on removal

[Chris Wilson]

Quoting Jani Nikula (2020-05-07 09:49:15)
> On Sun, 03 May 2020, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> > If the FBC is still writing into stolen, it will overwrite any future
> > users of that stolen region. Check before release.
> >
> > References: https://gitlab.freedesktop.org/drm/intel/-/issues/1635
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > ---
> >  drivers/gpu/drm/i915/display/intel_fbc.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c b/drivers/gpu/drm/i915/display/intel_fbc.c
> > index c6afa10e814c..37244ed92ae4 100644
> > --- a/drivers/gpu/drm/i915/display/intel_fbc.c
> > +++ b/drivers/gpu/drm/i915/display/intel_fbc.c
> > @@ -540,6 +540,9 @@ static void __intel_fbc_cleanup_cfb(struct drm_i915_private *dev_priv)
> >  {
> >       struct intel_fbc *fbc = &dev_priv->fbc;
> >  
> > +     if (WARN_ON(intel_fbc_hw_is_active(dev_priv)))
> 
> drm_WARN_ON() ;)

I'm hoping that by the time you get around to it, we will have a drm-tip
idle run which will tell us whether or not this is barking up the wrong
tree.
-Chris