@@ -612,6 +612,12 @@ static int gen8_ppgtt_enable(struct i915_hw_ppgtt *ppgtt)
for_each_ring(ring, dev_priv, j) {
I915_WRITE(RING_MODE_GEN7(ring),
_MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
+
+ /* We promise to do a switch later with FULL PPGTT. If this is
+ * aliasing, this is the one and only switch we'll do */
+ if (USES_FULL_PPGTT(dev))
+ continue;
+
ret = ppgtt->switch_mm(ppgtt, ring, true);
if (ret)
goto err_out;
@@ -651,11 +657,17 @@ static int gen7_ppgtt_enable(struct i915_hw_ppgtt *ppgtt)
/* GFX_MODE is per-ring on gen7+ */
I915_WRITE(RING_MODE_GEN7(ring),
_MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
+
+ /* We promise to do a switch later with FULL PPGTT. If this is
+ * aliasing, this is the one and only switch we'll do */
+ if (USES_FULL_PPGTT(dev))
+ continue;
+
ret = ppgtt->switch_mm(ppgtt, ring, true);
if (ret)
return ret;
-
}
+
return 0;
}
Originally this commit message said: Now that do_switch does the mm switch, and we always enable the aliasing PPGTT, and contexts at the same time, there is no need to continue doing this during PPGTT enabling. Since originally writing the patch however, I introduced the concept of synchronous mm switching (using MMIO). Since this is generally not recommended in the spec (for reasons unknown), I've isolated its usage as much as possible. As such the "extraneous" switch only ever will occur when we have full PPGTT. Signed-off-by: Ben Widawsky <ben@bwidawsk.net> --- drivers/gpu/drm/i915/i915_gem_gtt.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)