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dmaengine: Rework dma_chan_get

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dma_chan_get uses a rather interesting error handling and code path.

Change it to something more usual in the kernel.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Maxime Ripard 2014-11-17 14:41:58 +01:00 committed by Vinod Koul
parent ceacbdbf65
commit d2f4f99db3
1 changed files with 21 additions and 19 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

40
drivers/dma/dmaengine.c
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@ -222,31 +222,33 @@ static void balance_ref_count(struct dma_chan *chan)
*/ */
static int dma_chan_get(struct dma_chan *chan) static int dma_chan_get(struct dma_chan *chan)
{ {
int err = -ENODEV;
struct module *owner = dma_chan_to_owner(chan); struct module *owner = dma_chan_to_owner(chan);
int ret;
/* The channel is already in use, update client count */
if (chan->client_count) { if (chan->client_count) {
__module_get(owner); __module_get(owner);
err = 0; goto out;
} else if (try_module_get(owner))
err = 0;
if (err == 0)
chan->client_count++;
/* allocate upon first client reference */
if (chan->client_count == 1 && err == 0) {
int desc_cnt = chan->device->device_alloc_chan_resources(chan);
if (desc_cnt < 0) {
err = desc_cnt;
chan->client_count = 0;
module_put(owner);
} else if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
balance_ref_count(chan);
} }
return err; if (!try_module_get(owner))
return -ENODEV;
/* allocate upon first client reference */
ret = chan->device->device_alloc_chan_resources(chan);
if (ret < 0)
goto err_out;
if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
balance_ref_count(chan);
out:
chan->client_count++;
return 0;
err_out:
module_put(owner);
return ret;
} }
/** /**