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| author | Vinod Koul <vinod.koul@intel.com> | 2013-08-14 08:25:04 (GMT) |
|---|---|---|
| committer | Vinod Koul <vinod.koul@intel.com> | 2013-08-14 08:25:04 (GMT) |
| commit | aab81e47f58ea13f8bf7c1046670dd80566b1040 (patch) | |
| tree | cc603805419d35a0412186136f503374712db72d /drivers | |
| parent | 52a9d179109c50b1a5077cc2a653295fa131f0d0 (diff) | |
| parent | 7bb587f4eef8f71ce589f360ab99bb54ab0fc85d (diff) | |
| download | linux-aab81e47f58ea13f8bf7c1046670dd80566b1040.tar.xz | |
Merge branch 'topic/of' into for-linus
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/dma/dmaengine.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 9e56745..5932ab1 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -504,6 +504,32 @@ static struct dma_chan *private_candidate(const dma_cap_mask_t *mask, } /** + * dma_request_channel - try to get specific channel exclusively + * @chan: target channel + */ +struct dma_chan *dma_get_slave_channel(struct dma_chan *chan) +{ + int err = -EBUSY; + + /* lock against __dma_request_channel */ + mutex_lock(&dma_list_mutex); + + if (chan->client_count == 0) + err = dma_chan_get(chan); + else + chan = NULL; + + mutex_unlock(&dma_list_mutex); + + if (err) + pr_debug("%s: failed to get %s: (%d)\n", + __func__, dma_chan_name(chan), err); + + return chan; +} +EXPORT_SYMBOL_GPL(dma_get_slave_channel); + +/** * dma_request_channel - try to allocate an exclusive channel * @mask: capabilities that the channel must satisfy * @fn: optional callback to disposition available channels |