Am 10.08.19 um 17:34 schrieb Chris Wilson:
When one of the array of fences is signaled, propagate its errors to the parent fence-array (keeping the first error to be raised).
v2: Opencode cmpxchg_local to avoid compiler freakout.
Signed-off-by: Chris Wilson chris@chris-wilson.co.uk Cc: Sumit Semwal sumit.semwal@linaro.org Cc: Gustavo Padovan gustavo@padovan.org
drivers/dma-buf/dma-fence-array.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)
diff --git a/drivers/dma-buf/dma-fence-array.c b/drivers/dma-buf/dma-fence-array.c index 12c6f64c0bc2..d90675bb4fcc 100644 --- a/drivers/dma-buf/dma-fence-array.c +++ b/drivers/dma-buf/dma-fence-array.c @@ -13,6 +13,12 @@ #include <linux/slab.h> #include <linux/dma-fence-array.h>
+static void fence_set_error_once(struct dma_fence *fence, int error)
I would use a dma_fence_array prefix for all names in the file.
+{
- if (!fence->error && error)
dma_fence_set_error(fence, error);+}
- static const char *dma_fence_array_get_driver_name(struct dma_fence *fence) { return "dma_fence_array";
@@ -38,6 +44,13 @@ static void dma_fence_array_cb_func(struct dma_fence *f, container_of(cb, struct dma_fence_array_cb, cb); struct dma_fence_array *array = array_cb->array;
- /*
* Propagate the first error reported by any of our fences, but only* before we ourselves are signaled.*/- if (atomic_read(&array->num_pending) > 0)
fence_set_error_once(&array->base, f->error);
That is racy even if you check the atomic because num_pending can be initialized to 1 for signal any arrays as well.
I suggest to rather test in dma_fence_array_set_error_once if we got an error and if yes grab the sequence lock and test if we are already signaled or not.
Christian.
- if (atomic_dec_and_test(&array->num_pending)) irq_work_queue(&array->work); else
@@ -63,6 +76,8 @@ static bool dma_fence_array_enable_signaling(struct dma_fence *fence) dma_fence_get(&array->base); if (dma_fence_add_callback(array->fences[i], &cb[i].cb, dma_fence_array_cb_func)) {
fence_set_error_once(&array->base,array->fences[i]->error); dma_fence_put(&array->base); if (atomic_dec_and_test(&array->num_pending)) return false;