Re: [PATCH i-g-t 1/3] lib/kms: Introduce for_each_plane_format()

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

On Thu, Apr 16, 2026 at 06:44:05PM +0300, Jani Nikula wrote:
> On Thu, 16 Apr 2026, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> >
> > A few places want to iterate just the formats supported by a plane,
> > ignoring the modifier aspect entirely. Add a new iterator for this
> > (for_each_plane_format()) to avoid everyone just open coding it.
> >
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  lib/igt_kms.h | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> >
> > diff --git a/lib/igt_kms.h b/lib/igt_kms.h
> > index fcbb6a5ade3a..a58cb5cd3430 100644
> > --- a/lib/igt_kms.h
> > +++ b/lib/igt_kms.h
> > @@ -816,6 +816,18 @@ igt_output_crtc_t *__igt_output_crtc_populate(igt_display_t *display,
> >  	     (mode) < &(output)->config.connector->modes[(output)->config.connector->count_modes]; \
> >  	     (mode)++)
> >  
> > +/**
> > + * for_each_plane_format:
> > + * @plane: a pointer to an #igt_plane_t structure
> > + * @format: format iterator
> > + *
> > + * This for loop iterates over all formats supported by @plane.
> > + */
> > +#define for_each_plane_format(plane, format) \
> > +	for (int __i = 0; __i < (plane)->drm_plane->count_formats; __i++) \
> > +		for_each_if (((format) = (plane)->drm_plane->formats[__i], \
> > +			      1))
> 
> Using kernel-style __UNIQUE_ID() for __i would be nice to have, but I
> guess we don't have that facility in IGT.

We do (igt_unique()), but I didn't actually need it here so
didn't bother with it. I do have some other iterators lined
up where I did need nested use, and so used it there. I suppose
using it here too might make sense, just in case someone does
come up with some nested use case.

> Reviewed-by: Jani Nikula <jani.nikula@intel.com>
> 
> > +
> >  #define IGT_FIXED(i,f)	((i) << 16 | (f))
> >  
> >  /**
> 
> -- 
> Jani Nikula, Intel

-- 
Ville Syrjälä
Intel