[PATCH] drm/i915/display: Workaround for odd panning for planar yuv

[Garg, Nemesa]

> -----Original Message-----
> From: Kandpal, Suraj <suraj.kandpal at intel.com>
> Sent: Thursday, July 25, 2024 8:30 AM
> To: Garg, Nemesa <nemesa.garg at intel.com>; intel-xe at lists.freedesktop.org;
> intel-gfx at lists.freedesktop.org
> Cc: Heikkila, Juha-pekka <juha-pekka.heikkila at intel.com>; Shankar, Uma
> <uma.shankar at intel.com>; Garg, Nemesa <nemesa.garg at intel.com>
> Subject: RE: [PATCH] drm/i915/display: Workaround for odd panning for planar
> yuv
> 
> 
> 
> > -----Original Message-----
> > From: Kandpal, Suraj
> > Sent: Wednesday, July 24, 2024 10:32 PM
> > To: Nemesa Garg <nemesa.garg at intel.com>;
> > intel-xe at lists.freedesktop.org
> > Cc: Heikkila, Juha-pekka <juha-pekka.heikkila at intel.com>; Shankar, Uma
> > <uma.shankar at intel.com>; Garg, Nemesa <Nemesa.Garg at intel.com>
> > Subject: RE: [PATCH] drm/i915/display: Workaround for odd panning for
> > planar yuv
> >
> >
> >
> > > -----Original Message-----
> > > From: Intel-xe <intel-xe-bounces at lists.freedesktop.org> On Behalf Of
> > > Nemesa Garg
> > > Sent: Wednesday, July 24, 2024 6:36 PM
> > > To: intel-xe at lists.freedesktop.org
> > > Cc: Heikkila, Juha-pekka <juha-pekka.heikkila at intel.com>; Shankar,
> > > Uma <uma.shankar at intel.com>; Garg, Nemesa <nemesa.garg at intel.com>
> > > Subject: [PATCH] drm/i915/display: Workaround for odd panning for
> > > planar yuv
> > >
> > > Underrun/corruption issue is seen for NV12 format for odd panning on
> > > LNL due to hardware bug.
> > > Disable the format.
> >
> > When describing the commit for a WA no need to mention what the issue
> > is that is described In the WA number only describe what the patch is doing.
> >
> > >
> > > HSD: 16024459452
> >
> > Better to write this as
> > WA: 16024459452

> > > Sure I'll do.
> > > Signed-off-by: Nemesa Garg <nemesa.garg at intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/display/intel_atomic_plane.c | 8 ++++++++
> > >  1 file changed, 8 insertions(+)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> > > b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> > > index e979786aa5cf..f927e6a0b28b 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> > > @@ -1029,6 +1029,14 @@ int intel_plane_check_src_coordinates(struct
> > > intel_plane_state *plane_state)
> > >  		 * This allows NV12 and P0xx formats to have odd size
> > and/or odd
> > >  		 * source coordinates on DISPLAY_VER(i915) >= 20
> > >  		 */
> > > +
> > > +		/*
> > > +		 * Wa_16023981245 for display version 20.
> > > +		 * Disable odd pan for NV12 format.
> > > +		 */
> > > +		if (DISPLAY_VER(i915) == 20 && fb->format->format ==
> > > DRM_FORMAT_NV12)
> > > +			return 0;
> >
> > Also is this the correct implementation of this WA it says to disallow
> > odd xpan and disable even xsize I don't See xsize implementation anywhere.
> > Next is if we disable odd xpan shouldn't we then program it to allow
> > even xpan this returns without doing anything
> >
I'll add the implementation of even xsize.
As the odd pan is getting disable we wil return the einval (as it is not supported).
Then it depends upon user whether to set the position of videoplayback such that it takes even xpan or not.

Regards,
Nemesa
> > Regards,
> > Suraj Kandpal
> > > +
> > >  		hsub = 1;
> > >  		vsub = 1;
> > >  	} else {
> > > --
> > > 2.25.1