async_tx: fix the bug in async_tx_run_dependencies

Should clear the next pointer of the TX if we are sure that the
next TX (say NXT) will be submitted to the channel too. Overwise,
we break the chain of descriptors, because we lose the information
about the next descriptor to run. So next time, when invoke
async_tx_run_dependencies() with TX, it's TX->next will be NULL, and
NXT will be never submitted.

Cc: <stable@kernel.org>		[2.6.26]
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Yuri Tikhonov 2008-09-05 08:15:47 -07:00 committed by Dan Williams
parent b380b0d4f7
commit de24125dd0

View file

@ -137,7 +137,8 @@ async_tx_run_dependencies(struct dma_async_tx_descriptor *tx)
spin_lock_bh(&next->lock);
next->parent = NULL;
_next = next->next;
next->next = NULL;
if (_next && _next->chan == chan)
next->next = NULL;
spin_unlock_bh(&next->lock);
next->tx_submit(next);