On Tue, Aug 20, 2019 at 01:57:44PM -0700, Daniele Ceraolo Spurio wrote: > > > On 8/20/19 12:54 PM, Daniel Vetter wrote: > > The cpu (de)tiler hw is gone, this stopped being useful. Plus it never > > supported any of the fancy new tiling formats, which means userspace > > also stopped using the magic side-channel this provides. > > > > This would totally break a lot of the igts, but they're already broken > > for the same reasons as userspace on gen12 would be. > > > > v2: Look at ggtt->num_fences instead, that also avoids the need for a > > comment (Chris). This also means that gen12 support really needs to > > make sure num_fences is set to 0. There is a patch for that, but it > > checks for HAS_MAPPABLE_APERTURE, which I'm not sure is the right > > thing really. Adding relevant people. > > > > We'd obviously need to make that setting for all gen12+, because TGL > does have mappable aperture. > > Apart from the tiling ioctl, the only place I see where we set tiling is > intel_alloc_initial_plane_obj(), can the users of that object handle the > lack of fences gracefully?
Gen4+ display engine has its own tiling controls and doesn't care about fences. So we should be able to leave the obj tiling set to NONE. Hmm. Actually I think we should reject tiled framebuffers in the BIOS fb takeover because fbdev needs a linear view for the memory. No can do without the fence. > When I wrote the num_fences=0 patch I was > expecting display to be unavailable, so I didn't really look at that > part of the code. > > It'd also be nice to be more explicit with fencing since we seem to > often call i915_vma_pin_iomap, which implicitly applies a fence if > needed, on objects that can't be tiled or have had a fence assigned a > few lines before. This is more a nice to have tough, possibly together > with a split of the "mappable" and "fenceable" attributes of the vma. > > Daniele > > > Cc: Daniele Ceraolo Spurio <[email protected]> > > Cc: Stuart Summers <[email protected]> > > Cc: Matthew Auld <[email protected]> > > Cc: Kenneth Graunke <[email protected]> > > Cc: Jason Ekstrand <[email protected]> > > Cc: Chris Wilson <[email protected]> > > Cc: Lucas De Marchi <[email protected]> > > Signed-off-by: Daniel Vetter <[email protected]> > > --- > > drivers/gpu/drm/i915/gem/i915_gem_tiling.c | 7 +++++++ > > 1 file changed, 7 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_tiling.c > > b/drivers/gpu/drm/i915/gem/i915_gem_tiling.c > > index ca0c2f451742..e5d1ae8d4dba 100644 > > --- a/drivers/gpu/drm/i915/gem/i915_gem_tiling.c > > +++ b/drivers/gpu/drm/i915/gem/i915_gem_tiling.c > > @@ -313,10 +313,14 @@ int > > i915_gem_set_tiling_ioctl(struct drm_device *dev, void *data, > > struct drm_file *file) > > { > > + struct drm_i915_private *dev_priv = to_i915(dev); > > struct drm_i915_gem_set_tiling *args = data; > > struct drm_i915_gem_object *obj; > > int err; > > > > + if (!dev_priv->ggtt.num_fences) > > + return -EOPNOTSUPP; > > + > > obj = i915_gem_object_lookup(file, args->handle); > > if (!obj) > > return -ENOENT; > > @@ -402,6 +406,9 @@ i915_gem_get_tiling_ioctl(struct drm_device *dev, void > > *data, > > struct drm_i915_gem_object *obj; > > int err = -ENOENT; > > > > + if (!dev_priv->ggtt.num_fences) > > + return -EOPNOTSUPP; > > + > > rcu_read_lock(); > > obj = i915_gem_object_lookup_rcu(file, args->handle); > > if (obj) { > > > _______________________________________________ > Intel-gfx mailing list > [email protected] > https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Ville Syrjälä Intel _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
