Re: [PATCH v2 1/3] drm/i915/fbc: update the supported FP16 formats

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

On Tue, Oct 27, 2026 at 09:06:58AM +0000, Govindapillai, Vinod wrote:
> On Mon, 2026-10-26 at 17:15 +0200, Ville Syrjälä wrote:
> > On Mon, Oct 26, 2026 at 04:55:06PM +0200, Vinod Govindapillai wrote:
> > > FBC is supported with FP16 formats with or without alpha. At the
> > > same time modify the function name for the FP16 format check and
> > > simplify the FP16 format check calls.
> > > 
> > > Bspec: 68904
> > > Signed-off-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/display/intel_fbc.c | 21 +++++++-------------
> > > -
> > >  1 file changed, 7 insertions(+), 14 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c
> > > b/drivers/gpu/drm/i915/display/intel_fbc.c
> > > index 5694d20773f8..dbb16a9ec69d 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_fbc.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_fbc.c
> > > @@ -1180,14 +1180,15 @@ static bool
> > > lnl_fbc_pixel_format_is_valid(const struct intel_plane_state
> > > *plane_
> > >  	}
> > >  }
> > >  
> > > -static bool
> > > -xe3p_lpd_fbc_fp16_format_is_valid(const struct intel_plane_state
> > > *plane_state)
> > > +static bool intel_fbc_is_fp16_format(const struct
> > > intel_plane_state *plane_state)
> > >  {
> > >  	const struct drm_framebuffer *fb = plane_state->hw.fb;
> > >  
> > >  	switch (fb->format->format) {
> > >  	case DRM_FORMAT_ARGB16161616F:
> > > +	case DRM_FORMAT_XRGB16161616F:
> > >  	case DRM_FORMAT_ABGR16161616F:
> > > +	case DRM_FORMAT_XBGR16161616F:
> > >  		return true;
> > >  	default:
> > >  		return false;
> > > @@ -1196,24 +1197,16 @@ xe3p_lpd_fbc_fp16_format_is_valid(const
> > > struct intel_plane_state *plane_state)
> > >  
> > >  static bool xe3p_lpd_fbc_pixel_format_is_valid(const struct
> > > intel_plane_state *plane_state)
> > >  {
> > > -	if (lnl_fbc_pixel_format_is_valid(plane_state))
> > > -		return true;
> > > -
> > > -	if (xe3p_lpd_fbc_fp16_format_is_valid(plane_state))
> > > -		return true;
> > > -
> > > -	return false;
> > > +	return lnl_fbc_pixel_format_is_valid(plane_state) ||
> > > +	       intel_fbc_is_fp16_format(plane_state);
> > 
> > This is getting super messy. Would be much simpler to just list
> > the actual supported pixel formats here instead of trying to
> > this hard to follow inheritance thing.
> Ok. I will list all the formats as it is.
> 
> But pixel normalizer need to be enabled for fp16 formats, I think, it
> is better to group those as a separate reusable function. are you ok
> with that?

Hmm. I thought the format_info thing has a .is_float already, but
apparently not. We could add that. But in the meantime just a
some format_is_float() function should do.

-- 
Ville Syrjälä
Intel