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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>
This commit is contained in:
Dan Williams 2007-09-21 13:27:04 -07:00
parent c5d2b9f444
commit 6247cdc2cd
1 changed files with 10 additions and 2 deletions
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12
crypto/async_tx/async_tx.c
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@ -80,6 +80,7 @@ dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
{
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 @@ dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
/* 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));