drm/i915: Only do a chipset flush after a clflush
Now that we skip clflushes more often, return a boolean indicating
whether the clflush was actually performed, and only if it was do the
chipset flush. (Though on most of the architectures where the clflush will
be skipped, the chipset flush is a no-op!)
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 54d76e9..959dffb 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -841,8 +841,8 @@
*/
if (!needs_clflush_after &&
obj->base.write_domain != I915_GEM_DOMAIN_CPU) {
- i915_gem_clflush_object(obj, obj->pin_display);
- i915_gem_chipset_flush(dev);
+ if (i915_gem_clflush_object(obj, obj->pin_display))
+ i915_gem_chipset_flush(dev);
}
}
@@ -3224,7 +3224,7 @@
return ret;
}
-void
+bool
i915_gem_clflush_object(struct drm_i915_gem_object *obj,
bool force)
{
@@ -3233,14 +3233,14 @@
* again at bind time.
*/
if (obj->pages == NULL)
- return;
+ return false;
/*
* Stolen memory is always coherent with the GPU as it is explicitly
* marked as wc by the system, or the system is cache-coherent.
*/
if (obj->stolen)
- return;
+ return false;
/* If the GPU is snooping the contents of the CPU cache,
* we do not need to manually clear the CPU cache lines. However,
@@ -3251,11 +3251,12 @@
* tracking.
*/
if (!force && cpu_cache_is_coherent(obj->base.dev, obj->cache_level))
- return;
+ return false;
trace_i915_gem_object_clflush(obj);
-
drm_clflush_sg(obj->pages);
+
+ return true;
}
/** Flushes the GTT write domain for the object if it's dirty. */
@@ -3295,8 +3296,9 @@
if (obj->base.write_domain != I915_GEM_DOMAIN_CPU)
return;
- i915_gem_clflush_object(obj, force);
- i915_gem_chipset_flush(obj->base.dev);
+ if (i915_gem_clflush_object(obj, force))
+ i915_gem_chipset_flush(obj->base.dev);
+
old_write_domain = obj->base.write_domain;
obj->base.write_domain = 0;