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| author | Dan Williams <dan.j.williams@intel.com> | 2009-07-14 12:19:02 -0700 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2009-08-29 19:09:27 -0700 |
| commit | 95475e57113c66aac7583925736ed2e2d58c990d (patch) | |
| tree | 933aa0ca3bffef5b1457c516fbe3e8690b4c4cb1 /crypto | |
| parent | af1f951eb6ef27b01cbfb3f6c21b770af4368a6d (diff) | |
| download | linux-95475e57113c66aac7583925736ed2e2d58c990d.tar.gz linux-95475e57113c66aac7583925736ed2e2d58c990d.tar.bz2 linux-95475e57113c66aac7583925736ed2e2d58c990d.zip | |
async_tx: remove walk of tx->parent chain in dma_wait_for_async_tx
We currently walk the parent chain when waiting for a given tx to
complete however this walk may race with the driver cleanup routine.
The routines in async_raid6_recov.c may fall back to the synchronous
path at any point so we need to be prepared to call async_tx_quiesce()
(which calls dma_wait_for_async_tx). To remove the ->parent walk we
guarantee that every time a dependency is attached ->issue_pending() is
invoked, then we can simply poll the initial descriptor until
completion.
This also allows for a lighter weight 'issue pending' implementation as
there is no longer a requirement to iterate through all the channels'
->issue_pending() routines as long as operations have been submitted in
an ordered chain. async_tx_issue_pending() is added for this case.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/async_tx/async_tx.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c index 6e37ad3f4417..60615fedcf5e 100644 --- a/crypto/async_tx/async_tx.c +++ b/crypto/async_tx/async_tx.c @@ -77,8 +77,8 @@ static void async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx, struct dma_async_tx_descriptor *tx) { - struct dma_chan *chan; - struct dma_device *device; + struct dma_chan *chan = depend_tx->chan; + struct dma_device *device = chan->device; struct dma_async_tx_descriptor *intr_tx = (void *) ~0; /* first check to see if we can still append to depend_tx */ @@ -90,11 +90,11 @@ async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx, } spin_unlock_bh(&depend_tx->lock); - if (!intr_tx) + /* attached dependency, flush the parent channel */ + if (!intr_tx) { + device->device_issue_pending(chan); return; - - chan = depend_tx->chan; - device = chan->device; + } /* see if we can schedule an interrupt * otherwise poll for completion @@ -128,6 +128,7 @@ async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx, intr_tx->tx_submit(intr_tx); async_tx_ack(intr_tx); } + device->device_issue_pending(chan); } else { if (dma_wait_for_async_tx(depend_tx) == DMA_ERROR) panic("%s: DMA_ERROR waiting for depend_tx\n", |