| Message ID | 20220621200058.3536182-4-bob.beckett@collabora.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: ttm for stolen | expand |
On 6/21/22 22:00, Robert Beckett wrote: > By default i915_ttm_cache_level() decides I915_CACHE_LLC if HAS_SNOOP. > This is divergent from existing backends code which only considers > HAS_LLC. > Testing shows that trusting snooping on gen5- is unreliable and bsw via > ggtt mappings, so limit DGFX for now and maintain previous behaviour. Yeah, IIRC Matthew mentioned that HAS_SNOOP() can be overridden in various ways, but not on DGFX, (at least not for DG1). So this looks correct to me. > > Signed-off-by: Robert Beckett <bob.beckett@collabora.com> Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> > --- > drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c > index 4c1de0b4a10f..40249fa28a7a 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c > @@ -46,7 +46,9 @@ static enum i915_cache_level > i915_ttm_cache_level(struct drm_i915_private *i915, struct ttm_resource *res, > struct ttm_tt *ttm) > { > - return ((HAS_LLC(i915) || HAS_SNOOP(i915)) && > + bool can_snoop = HAS_SNOOP(i915) && IS_DGFX(i915); > + > + return ((HAS_LLC(i915) || can_snoop) && > !i915_ttm_gtt_binds_lmem(res) && > ttm->caching == ttm_cached) ? I915_CACHE_LLC : > I915_CACHE_NONE;
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c index 4c1de0b4a10f..40249fa28a7a 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c @@ -46,7 +46,9 @@ static enum i915_cache_level i915_ttm_cache_level(struct drm_i915_private *i915, struct ttm_resource *res, struct ttm_tt *ttm) { - return ((HAS_LLC(i915) || HAS_SNOOP(i915)) && + bool can_snoop = HAS_SNOOP(i915) && IS_DGFX(i915); + + return ((HAS_LLC(i915) || can_snoop) && !i915_ttm_gtt_binds_lmem(res) && ttm->caching == ttm_cached) ? I915_CACHE_LLC : I915_CACHE_NONE;
By default i915_ttm_cache_level() decides I915_CACHE_LLC if HAS_SNOOP. This is divergent from existing backends code which only considers HAS_LLC. Testing shows that trusting snooping on gen5- is unreliable and bsw via ggtt mappings, so limit DGFX for now and maintain previous behaviour. Signed-off-by: Robert Beckett <bob.beckett@collabora.com> --- drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)