drm/i915: Reset semaphore page for gen8

An oversight is that when we wrap the seqno, we need to reset the hw
semaphore counters to 0. We did this for gen6 and gen7 and forgot to do
so for the new implementation required for gen8 (legacy).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460010558-10705-6-git-send-email-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 69852ac4018d9c5e47ee26f66536753475103f86..0e64900740114b8827f7397020d26ec9cc6bcf15 100644 (file)
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2566,6 +2566,14 @@ void intel_ring_init_seqno(struct intel_engine_cs *engine, u32 seqno)
                if (HAS_VEBOX(dev_priv))
                        I915_WRITE(RING_SYNC_2(engine->mmio_base), 0);
        }
+       if (dev_priv->semaphore_obj) {
+               struct drm_i915_gem_object *obj = dev_priv->semaphore_obj;
+               struct page *page = i915_gem_object_get_dirty_page(obj, 0);
+               void *semaphores = kmap(page);
+               memset(semaphores + GEN8_SEMAPHORE_OFFSET(engine->id, 0),
+                      0, I915_NUM_ENGINES * gen8_semaphore_seqno_size);
+               kunmap(page);
+       }
        memset(engine->semaphore.sync_seqno, 0,
               sizeof(engine->semaphore.sync_seqno));