drm/i915: swizzling support for snb/ivb
We have to do this manually. Somebody had a Great Idea.
I've measured speed-ups just a few percent above the noise level
(below 5% for the best case), but no slowdows. Chris Wilson measured
quite a bit more (10-20% above the usual snb variance) on a more
recent and better tuned version of sna, but also recorded a few
slow-downs on benchmarks know for uglier amounts of snb-induced
variance.
v2: Incorporate Ben Widawsky's preliminary review comments and
elaborate a bit about the performance impact in the changelog.
v3: Add a comment as to why we don't need to check the 3rd memory
channel.
v4: Fixup whitespace.
Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 1658cfd..12ddf47 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -495,7 +495,7 @@
mutex_lock(&dev->struct_mutex);
dev_priv->mm.suspended = 0;
- error = i915_gem_init_ringbuffer(dev);
+ error = i915_gem_init_hw(dev);
mutex_unlock(&dev->struct_mutex);
if (HAS_PCH_SPLIT(dev))
@@ -686,6 +686,8 @@
!dev_priv->mm.suspended) {
dev_priv->mm.suspended = 0;
+ i915_gem_init_swizzling(dev);
+
dev_priv->ring[RCS].init(&dev_priv->ring[RCS]);
if (HAS_BSD(dev))
dev_priv->ring[VCS].init(&dev_priv->ring[VCS]);