SH: fix error paths in DMA driver

If channel allocation is failing, mark the channel unused and give PM a chance
to power down the hardware.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 21 insertions, 6 deletions

diff --git a/drivers/dma/shdma.c b/drivers/dma/shdma.c
index 7cc31b3f40d8..6f25a20de99f 100644
--- a/drivers/dma/shdma.c
+++ b/drivers/dma/shdma.c
@@ -290,6 +290,7 @@ static int sh_dmae_alloc_chan_resources(struct dma_chan *chan)
         struct sh_dmae_chan *sh_chan = to_sh_chan(chan);
         struct sh_desc *desc;
         struct sh_dmae_slave *param = chan->private;
+        int ret;
 
         pm_runtime_get_sync(sh_chan->dev);
 
@@ -301,11 +302,15 @@ static int sh_dmae_alloc_chan_resources(struct dma_chan *chan)
                 struct sh_dmae_slave_config *cfg;
 
                 cfg = sh_dmae_find_slave(sh_chan, param->slave_id);
-                if (!cfg)
-                        return -EINVAL;
+                if (!cfg) {
+                        ret = -EINVAL;
+                        goto efindslave;
+                }
 
-                if (test_and_set_bit(param->slave_id, sh_dmae_slave_used))
-                        return -EBUSY;
+                if (test_and_set_bit(param->slave_id, sh_dmae_slave_used)) {
+                        ret = -EBUSY;
+                        goto etestused;
+                }
 
                 param->config = cfg;
 
@@ -334,10 +339,20 @@ static int sh_dmae_alloc_chan_resources(struct dma_chan *chan)
         }
         spin_unlock_bh(&sh_chan->desc_lock);
 
-        if (!sh_chan->descs_allocated)
-                pm_runtime_put(sh_chan->dev);
+        if (!sh_chan->descs_allocated) {
+                ret = -ENOMEM;
+                goto edescalloc;
+        }
 
         return sh_chan->descs_allocated;
+
+edescalloc:
+        if (param)
+                clear_bit(param->slave_id, sh_dmae_slave_used);
+etestused:
+efindslave:
+        pm_runtime_put(sh_chan->dev);
+        return ret;
 }
 
 /*