[Intel-gfx] [PATCH 3/7] drm/i915: set num_fence_regs to 0 if there is no aperture

[Chris Wilson]

Quoting Daniele Ceraolo Spurio (2019-10-29 21:23:16)
> 
> 
> On 10/29/19 2:58 AM, Matthew Auld wrote:
> > From: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> > 
> > We can't fence anything without aperture.
> > 
> > Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> > Signed-off-by: Stuart Summers <stuart.summers at intel.com>
> > Signed-off-by: Matthew Auld <matthew.auld at intel.com>
> > ---
> >   drivers/gpu/drm/i915/i915_gem_fence_reg.c | 6 ++++--
> >   1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_gem_fence_reg.c b/drivers/gpu/drm/i915/i915_gem_fence_reg.c
> > index 321189e1b0f2..71efccfde122 100644
> > --- a/drivers/gpu/drm/i915/i915_gem_fence_reg.c
> > +++ b/drivers/gpu/drm/i915/i915_gem_fence_reg.c
> > @@ -846,8 +846,10 @@ void i915_ggtt_init_fences(struct i915_ggtt *ggtt)
> >   
> >       detect_bit_6_swizzle(ggtt);
> >   
> > -     if (INTEL_GEN(i915) >= 7 &&
> > -         !(IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915)))
> > +     if (!i915_ggtt_has_aperture(ggtt))
> 
> Daniel had mentioned that the fencing HW has been nerfed in gen12 and 
> suggested settings num_fences to zero for all gen12+. Should we go 
> directly with that?

Do fences exist, yes/no? If there are literally no fences forevermore...
tgl begs to differ though.
-Chris