drm/i915: don't enable the gen6 bsd ring tail write enable on gen7

HW engineers have fixed this issue for ivb. Again, a nice cleanup
possible thanks to the more flexible ring initialization.

Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 7e1f221..68e1255 100644 (file)
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1415,9 +1415,12 @@ int intel_init_bsd_ring_buffer(struct drm_device *dev)
        ring->name = "bsd ring";
        ring->id = VCS;
 
+       ring->write_tail = ring_write_tail;
        if (IS_GEN6(dev) || IS_GEN7(dev)) {
                ring->mmio_base = GEN6_BSD_RING_BASE;
-               ring->write_tail = gen6_bsd_ring_write_tail;
+               /* gen6 bsd needs a special wa for tail updates */
+               if (IS_GEN6(dev))
+                       ring->write_tail = gen6_bsd_ring_write_tail;
                ring->flush = gen6_ring_flush;
                ring->add_request = gen6_add_request;
                ring->get_seqno = gen6_ring_get_seqno;
@@ -1433,7 +1436,6 @@ int intel_init_bsd_ring_buffer(struct drm_device *dev)
                ring->signal_mbox[1] = GEN6_BVSYNC;
        } else {
                ring->mmio_base = BSD_RING_BASE;
-               ring->write_tail = ring_write_tail;
                ring->flush = bsd_ring_flush;
                ring->add_request = ring_add_request;
                ring->get_seqno = ring_get_seqno;