[bisected] commit 176f28eb breaks my Sandybridge

Commit Message

Carl Worth Nov. 4, 2010, 11:03 p.m. UTC

None

Patch

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/inte
index 8eaa60c..e88214e 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -176,9 +176,10 @@  static int init_ring_common(struct intel_ring_buffer *ring)
                        ((ring->gem_object->size - PAGE_SIZE) & RING_NR_PAGES)
                        | RING_NO_REPORT | RING_VALID);
 
-       head = I915_READ_HEAD(ring) & HEAD_ADDR;
        /* If the head is still not zero, the ring is dead */
-       if (head != 0) {
+       if ((I915_READ_CTL(ring) & RING_VALID) == 0 ||
+           I915_READ_START(ring) != obj_priv->gtt_offset ||
+           (I915_READ_HEAD(ring) & HEAD_ADDR) != 0) {
                DRM_ERROR("%s initialization failed "
                                "ctl %08x head %08x tail %08x start %08x\n",
                                ring->name,