[igt-dev] [PATCH i-g-t 2/3] lib/igt_fb: Use render copy/blit for tiled formats on platforms w/o HW detiling

[Imre Deak]

On Tue, Jan 21, 2020 at 06:19:30PM +0200, Juha-Pekka Heikkila wrote:
> On 21.1.2020 0.03, Imre Deak wrote:
> > On platforms without HW detiling use render copy or blitting to convert
> > between a tiled and a linear framebuffer.
> > 
> > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > ---
> >   lib/igt_fb.c | 16 +++++++++++++---
> >   1 file changed, 13 insertions(+), 3 deletions(-)
> > 
> > diff --git a/lib/igt_fb.c b/lib/igt_fb.c
> > index c81b9de8..b5b1750e 100644
> > --- a/lib/igt_fb.c
> > +++ b/lib/igt_fb.c
> > @@ -1975,17 +1975,27 @@ static bool blitter_ok(const struct igt_fb *fb)
> >   	return true;
> >   }
> > +static bool hw_can_detile(const struct igt_fb *fb)
> > +{
> > +	if (fb->modifier == DRM_FORMAT_MOD_NONE)
> > +		return true;
> > +
> > +	if (!gem_has_legacy_hw_tiling(fb->fd))
> > +		return false;
> > +
> > +	return fb->modifier != I915_FORMAT_MOD_Yf_TILED;
> 
> Should above line depend on gen? Like
> return (gen < 12 || fb->modifier != I915_FORMAT_MOD_Yf_TILED); ?

AFAIK no platform can detile the Yf format (only X or Y), but this
shouldn't change the logic in any case, except for
!gem_has_legacy_hw_tiling().

> 
> > +}
> > +
> >   static bool use_enginecopy(const struct igt_fb *fb)
> >   {
> >   	return is_ccs_modifier(fb->modifier) ||
> > -		(fb->modifier == I915_FORMAT_MOD_Yf_TILED &&
> > -		 !blitter_ok(fb));
> > +		(!hw_can_detile(fb) && !blitter_ok(fb));
> >   }
> >   static bool use_blitter(const struct igt_fb *fb)
> >   {
> >   	return (fb->modifier == I915_FORMAT_MOD_Y_TILED ||
> > -		fb->modifier == I915_FORMAT_MOD_Yf_TILED) &&
> > +		!hw_can_detile(fb)) &&
> >   		blitter_ok(fb);
> >   }
> > 
>