On retiring the request, we should not re-use these elements in the ring
(at least not until we fill the ringbuffer and knowingly reuse the space).
Leave behind some poison to (hopefully) trap ourselves if we make a
mistake.
Suggested-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_request.c | 26 +++++++++++++++++---------
1 file changed, 17 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 0ecc2cf64216..9ee7bf0200b0 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -203,6 +203,19 @@ static void free_capture_list(struct i915_request *request)
}
}
+static void __i915_request_fill(struct i915_request *rq, u8 val)
+{
+ void *vaddr = rq->ring->vaddr;
+ u32 head;
+
+ head = rq->infix;
+ if (rq->postfix < head) {
+ memset(vaddr + head, val, rq->ring->size - head);
+ head = 0;
+ }
+ memset(vaddr + head, val, rq->postfix - head);
+}
+
static void remove_from_engine(struct i915_request *rq)
{
struct intel_engine_cs *engine, *locked;
@@ -247,6 +260,9 @@ bool i915_request_retire(struct i915_request *rq)
*/
GEM_BUG_ON(!list_is_first(&rq->link,
&i915_request_timeline(rq)->requests));
+ if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM))
+ /* Poison before we release our space in the ring */
+ __i915_request_fill(rq, POISON_FREE);
rq->ring->head = rq->postfix;
/*
@@ -1175,9 +1191,6 @@ i915_request_await_object(struct i915_request *to,
void i915_request_skip(struct i915_request *rq, int error)
{
- void *vaddr = rq->ring->vaddr;
- u32 head;
-
GEM_BUG_ON(!IS_ERR_VALUE((long)error));
dma_fence_set_error(&rq->fence, error);
@@ -1189,12 +1202,7 @@ void i915_request_skip(struct i915_request *rq, int error)
* context, clear out all the user operations leaving the
* breadcrumb at the end (so we get the fence notifications).
*/
- head = rq->infix;
- if (rq->postfix < head) {
- memset(vaddr + head, 0, rq->ring->size - head);
- head = 0;
- }
- memset(vaddr + head, 0, rq->postfix - head);
+ __i915_request_fill(rq, 0);
rq->infix = rq->postfix;
}
--
2.25.0
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