drm/i915: Poison the request before emitting commands

If we poison the request before we emit commands, it should be easier to
spot when we execute an uninitialised request.

References: https://bugs.freedesktop.org/show_bug.cgi?id=100144
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170423170619.7156-2-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 227dfcf1764e..6836efb7e3d2 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1694,6 +1694,7 @@ u32 *intel_ring_begin(struct drm_i915_gem_request *req, int num_dwords)
 
         GEM_BUG_ON(ring->emit > ring->size - bytes);
         cs = ring->vaddr + ring->emit;
+        GEM_DEBUG_EXEC(memset(cs, POISON_INUSE, bytes));
         ring->emit += bytes;
         ring->space -= bytes;
         GEM_BUG_ON(ring->space < 0);