async_tx: fix dma_wait_for_async_tx
Fix dma_wait_for_async_tx to not loop forever in the case where a
dependency chain is longer than two entries. This condition will not
happen with current in-kernel drivers, but fix it for future drivers.
Found-by: Saeed Bishara <saeed.bishara@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c
index 0350071..bc18cbb 100644
--- a/crypto/async_tx/async_tx.c
+++ b/crypto/async_tx/async_tx.c
@@ -80,6 +80,7 @@
{
enum dma_status status;
struct dma_async_tx_descriptor *iter;
+ struct dma_async_tx_descriptor *parent;
if (!tx)
return DMA_SUCCESS;
@@ -87,8 +88,15 @@
/* poll through the dependency chain, return when tx is complete */
do {
iter = tx;
- while (iter->cookie == -EBUSY)
- iter = iter->parent;
+
+ /* find the root of the unsubmitted dependency chain */
+ while (iter->cookie == -EBUSY) {
+ parent = iter->parent;
+ if (parent && parent->cookie == -EBUSY)
+ iter = iter->parent;
+ else
+ break;
+ }
status = dma_sync_wait(iter->chan, iter->cookie);
} while (status == DMA_IN_PROGRESS || (iter != tx));
