Re: [PATCH 1/4] drm/i915: Drop 64bpp YUV formats from ICL+ SDR planes

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

On Tue, Dec 31, 2024 at 08:01:21PM +0530, Vodapalli, Ravi Kumar wrote:
> 
> 
> 
> On 12/18/2024 11:06 PM, Ville Syrjala wrote:
> > From: Ville Syrjälä<ville.syrjala@linux.intel.com>
> >
> > I'm seeing underruns with these 64bpp YUV formats on TGL.
> >
> > The weird details:
> > - only happens on pipe B/C/D SDR planes, pipe A SDR planes
> >    seem fine, as do all HDR planes
> > - somehow CDCLK related, higher CDCLK allows for bigger plane
> >    with these formats without underruns. With 300MHz CDCLK I
> >    can only go up to 1200 pixels wide or so, with 650MHz even
> >    a 3840 pixel wide plane was OK
> > - ICL and ADL so far appear unaffected
> >
> > So not really sure what's the deal with this, but bspec does
> > state "64-bit formats supported only on the HDR planes" so
> > let's just drop these formats from the SDR planes. We already
> > disallow 64bpp RGB formats.
> >
> > Cc:stable@vger.kernel.org
> > Signed-off-by: Ville Syrjälä<ville.syrjala@linux.intel.com>
> > ---
> >   drivers/gpu/drm/i915/display/skl_universal_plane.c | 4 ----
> >   1 file changed, 4 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/display/skl_universal_plane.c b/drivers/gpu/drm/i915/display/skl_universal_plane.c
> > index ff9764cac1e7..80e558042d97 100644
> > --- a/drivers/gpu/drm/i915/display/skl_universal_plane.c
> > +++ b/drivers/gpu/drm/i915/display/skl_universal_plane.c
> > @@ -106,8 +106,6 @@ static const u32 icl_sdr_y_plane_formats[] = {
> >   	DRM_FORMAT_Y216,
> >   	DRM_FORMAT_XYUV8888,
> >   	DRM_FORMAT_XVYU2101010,
> > -	DRM_FORMAT_XVYU12_16161616,
> > -	DRM_FORMAT_XVYU16161616,
> >   };
> 
> If we are seeing underrun on TGL platform only then better would be if 
> we define separate variable similar to
> icl_sdr_y_plane_formats since this variable is used for other platforms 
>  >= 11

Meh. Docs say this shouldn't really be supported in the first place
so I'm inclined to just nuke it across the board. I suspect no one
will actually notice.

> 
> >   
> >   static const u32 icl_sdr_uv_plane_formats[] = {
> > @@ -134,8 +132,6 @@ static const u32 icl_sdr_uv_plane_formats[] = {
> >   	DRM_FORMAT_Y216,
> >   	DRM_FORMAT_XYUV8888,
> >   	DRM_FORMAT_XVYU2101010,
> > -	DRM_FORMAT_XVYU12_16161616,
> > -	DRM_FORMAT_XVYU16161616,
> >   };
> 
> same as above define separate variable
> 
> Regards
> Ravi Kumar V
> 
> >   
> >   static const u32 icl_hdr_plane_formats[] = {

-- 
Ville Syrjälä
Intel