dmaengine: core: Move and merge the code paths using private_candidate

Channel matching with private_candidate() is used in two paths, the error
checking is slightly different in them and they are duplicating code also.
Move the code under find_candidate() to provide consistent execution and
going to allow us to reuse this mode of channel lookup later.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index f2cbff95b56ef831ffb85c1e41f5657740d99084..81a36fc445a7537fb3bbf498124a09a4ccc65684 100644 (file)
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -542,6 +542,42 @@ static struct dma_chan *private_candidate(const dma_cap_mask_t *mask,
        return NULL;
 }
 
+static struct dma_chan *find_candidate(struct dma_device *device,
+                                      const dma_cap_mask_t *mask,
+                                      dma_filter_fn fn, void *fn_param)
+{
+       struct dma_chan *chan = private_candidate(mask, device, fn, fn_param);
+       int err;
+
+       if (chan) {
+               /* Found a suitable channel, try to grab, prep, and return it.
+                * We first set DMA_PRIVATE to disable balance_ref_count as this
+                * channel will not be published in the general-purpose
+                * allocator
+                */
+               dma_cap_set(DMA_PRIVATE, device->cap_mask);
+               device->privatecnt++;
+               err = dma_chan_get(chan);
+
+               if (err) {
+                       if (err == -ENODEV) {
+                               pr_debug("%s: %s module removed\n", __func__,
+                                        dma_chan_name(chan));
+                               list_del_rcu(&device->global_node);
+                       } else
+                               pr_debug("%s: failed to get %s: (%d)\n",
+                                        __func__, dma_chan_name(chan), err);
+
+                       if (--device->privatecnt == 0)
+                               dma_cap_clear(DMA_PRIVATE, device->cap_mask);
+
+                       chan = ERR_PTR(err);
+               }
+       }
+
+       return chan ? chan : ERR_PTR(-EPROBE_DEFER);
+}
+
 /**
  * dma_get_slave_channel - try to get specific channel exclusively
  * @chan: target channel
@@ -580,7 +616,6 @@ struct dma_chan *dma_get_any_slave_channel(struct dma_device *device)
 {
        dma_cap_mask_t mask;
        struct dma_chan *chan;
-       int err;
 
        dma_cap_zero(mask);
        dma_cap_set(DMA_SLAVE, mask);
@@ -588,23 +623,11 @@ struct dma_chan *dma_get_any_slave_channel(struct dma_device *device)
        /* lock against __dma_request_channel */
        mutex_lock(&dma_list_mutex);
 
-       chan = private_candidate(&mask, device, NULL, NULL);
-       if (chan) {
-               dma_cap_set(DMA_PRIVATE, device->cap_mask);
-               device->privatecnt++;
-               err = dma_chan_get(chan);
-               if (err) {
-                       pr_debug("%s: failed to get %s: (%d)\n",
-                               __func__, dma_chan_name(chan), err);
-                       chan = NULL;
-                       if (--device->privatecnt == 0)
-                               dma_cap_clear(DMA_PRIVATE, device->cap_mask);
-               }
-       }
+       chan = find_candidate(device, &mask, NULL, NULL);
 
        mutex_unlock(&dma_list_mutex);
 
-       return chan;
+       return IS_ERR(chan) ? NULL : chan;
 }
 EXPORT_SYMBOL_GPL(dma_get_any_slave_channel);
 
@@ -621,35 +644,15 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
 {
        struct dma_device *device, *_d;
        struct dma_chan *chan = NULL;
-       int err;
 
        /* Find a channel */
        mutex_lock(&dma_list_mutex);
        list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
-               chan = private_candidate(mask, device, fn, fn_param);
-               if (chan) {
-                       /* Found a suitable channel, try to grab, prep, and
-                        * return it.  We first set DMA_PRIVATE to disable
-                        * balance_ref_count as this channel will not be
-                        * published in the general-purpose allocator
-                        */
-                       dma_cap_set(DMA_PRIVATE, device->cap_mask);
-                       device->privatecnt++;
-                       err = dma_chan_get(chan);
+               chan = find_candidate(device, mask, fn, fn_param);
+               if (!IS_ERR(chan))
+                       break;
 
-                       if (err == -ENODEV) {
-                               pr_debug("%s: %s module removed\n",
-                                        __func__, dma_chan_name(chan));
-                               list_del_rcu(&device->global_node);
-                       } else if (err)
-                               pr_debug("%s: failed to get %s: (%d)\n",
-                                        __func__, dma_chan_name(chan), err);
-                       else
-                               break;
-                       if (--device->privatecnt == 0)
-                               dma_cap_clear(DMA_PRIVATE, device->cap_mask);
-                       chan = NULL;
-               }
+               chan = NULL;
        }
        mutex_unlock(&dma_list_mutex);