[Intel-gfx] [PATCH] drm/i915: Preallocate request before access of the ring

[yu.dai at intel.com]

From: Alex Dai <yu.dai at intel.com>

This is to avoid bad IO access caused by writing NOOP to wrap the
ring buffer whilst ring is unpinned.

Signed-off-by: Alex Dai <yu.dai at intel.com>
---
 drivers/gpu/drm/i915/intel_lrc.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 732fd63..3e8fcfd 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -803,12 +803,12 @@ static int intel_logical_ring_begin(struct intel_ringbuffer *ringbuf,
 	if (ret)
 		return ret;
 
-	ret = logical_ring_prepare(ringbuf, ctx, num_dwords * sizeof(uint32_t));
+	/* Preallocate the olr before touching the ring */
+	ret = i915_gem_request_alloc(ring, ctx);
 	if (ret)
 		return ret;
 
-	/* Preallocate the olr before touching the ring */
-	ret = i915_gem_request_alloc(ring, ctx);
+	ret = logical_ring_prepare(ringbuf, ctx, num_dwords * sizeof(uint32_t));
 	if (ret)
 		return ret;
 
-- 
1.9.1