Re: [Intel-gfx] [PATCH] drm/i915: Ensure dbuf state is defined

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Wed, Oct 05, 2022 at 12:25:26PM +0000, Kahola, Mika wrote:
> > -----Original Message-----
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > Sent: Wednesday, October 5, 2022 2:29 PM
> > To: Kahola, Mika <mika.kahola@intel.com>
> > Cc: intel-gfx@lists.freedesktop.org
> > Subject: Re: [Intel-gfx] [PATCH] drm/i915: Ensure dbuf state is defined
> > 
> > On Wed, Oct 05, 2022 at 02:11:58PM +0300, Mika Kahola wrote:
> > > Ensure that the new dbuf state is not null. If so, throw an error,
> > > discontinue to allocate ddb and return.
> > >
> > > Signed-off-by: Mika Kahola <mika.kahola@intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/display/skl_watermark.c | 3 +++
> > >  1 file changed, 3 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c
> > > b/drivers/gpu/drm/i915/display/skl_watermark.c
> > > index d58e667016e4..4ecf3b43d6d2 100644
> > > --- a/drivers/gpu/drm/i915/display/skl_watermark.c
> > > +++ b/drivers/gpu/drm/i915/display/skl_watermark.c
> > > @@ -638,6 +638,9 @@ skl_crtc_allocate_ddb(struct intel_atomic_state
> > *state, struct intel_crtc *crtc)
> > >  	u32 start, end;
> > >  	int ret;
> > >
> > > +	if (IS_ERR(new_dbuf_state))
> > > +		return PTR_ERR(new_dbuf_state);
> > > +
> > 
> > You can't get here without the dbuf_state. Also even if we didn't have one
> > intel_atomic_get_new_dbuf_state() certainly shouldn't give us an error pointer
> > (you either get a valid pointer or NULL).
> Ok, so we can get a null here. Should we add a check for that one?

We can't get a null unless there is a bug somewhere. Is there one?

> 
> > 
> > >  	if (new_dbuf_state->weight[pipe] == 0) {
> > >  		skl_ddb_entry_init(&new_dbuf_state->ddb[pipe], 0, 0);
> > >  		goto out;
> > > --
> > > 2.34.1
> > 
> > --
> > Ville Syrjälä
> > Intel

-- 
Ville Syrjälä
Intel