[PATCH v3 04/59] dmaengine: Rework dma_chan_get

Maxime Ripard
2014-10-22T16:13:13Z

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>
---
drivers/dma/dmaengine.c | 36 +++++++++++++++++++-----------------
1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 24bfaf0b92ba..72f10e2f5c32 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -222,31 +222,33 @@ static void balance_ref_count(struct dma_chan *chan)
*/
static int dma_chan_get(struct dma_chan *chan)
{
- int err = -ENODEV;
struct module *owner = dma_chan_to_owner(chan);
+ int ret;

+ /* The channel is already in use, update client count */
if (chan->client_count) {
__module_get(owner);
- err = 0;
- } else if (try_module_get(owner))
- err = 0;
+ goto out;
+ }

- if (err == 0)
- chan->client_count++;
+ if (!try_module_get(owner))
+ return -ENODEV;

/* 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);
- }
+ ret = chan->device->device_alloc_chan_resources(chan);
+ if (ret < 0)
+ goto err_out;

- return err;
+ 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;
}

/**
--
2.1.1