dmaengine: Rework dma_chan_get

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>

1 files changed, 19 insertions, 17 deletions

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index e057935e3023..a5da0e147560 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;
 }
 
 /**