1 files changed, 46 insertions, 62 deletions

diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index 526579df6033..d300de456c90 100644
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c
@@ -882,65 +882,15 @@ static void fsldma_cleanup_descriptor(struct fsldma_chan *chan,
 }
 
 /**
- * fsl_chan_ld_cleanup - Clean up link descriptors
- * @chan : Freescale DMA channel
- *
- * This function is run after the queue of running descriptors has been
- * executed by the DMA engine. It will run any callbacks, and then free
- * the descriptors.
- *
- * HARDWARE STATE: idle
- */
-static void fsl_chan_ld_cleanup(struct fsldma_chan *chan)
-{
-        struct fsl_desc_sw *desc, *_desc;
-        LIST_HEAD(ld_cleanup);
-        unsigned long flags;
-
-        spin_lock_irqsave(&chan->desc_lock, flags);
-
-        /* update the cookie if we have some descriptors to cleanup */
-        if (!list_empty(&chan->ld_running)) {
-                dma_cookie_t cookie;
-
-                desc = to_fsl_desc(chan->ld_running.prev);
-                cookie = desc->async_tx.cookie;
-
-                chan->completed_cookie = cookie;
-                chan_dbg(chan, "completed cookie=%d\n", cookie);
-        }
-
-        /*
-         * move the descriptors to a temporary list so we can drop the lock
-         * during the entire cleanup operation
-         */
-        list_splice_tail_init(&chan->ld_running, &ld_cleanup);
-
-        spin_unlock_irqrestore(&chan->desc_lock, flags);
-
-        /* Run the callback for each descriptor, in order */
-        list_for_each_entry_safe(desc, _desc, &ld_cleanup, node) {
-
-                /* Remove from the list of transactions */
-                list_del(&desc->node);
-
-                /* Run all cleanup for this descriptor */
-                fsldma_cleanup_descriptor(chan, desc);
-        }
-}
-
-/**
  * fsl_chan_xfer_ld_queue - transfer any pending transactions
  * @chan : Freescale DMA channel
  *
  * HARDWARE STATE: idle
+ * LOCKING: must hold chan->desc_lock
  */
 static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
 {
         struct fsl_desc_sw *desc;
-        unsigned long flags;
-
-        spin_lock_irqsave(&chan->desc_lock, flags);
 
         /*
          * If the list of pending descriptors is empty, then we
@@ -948,7 +898,7 @@ static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
          */
         if (list_empty(&chan->ld_pending)) {
                 chan_dbg(chan, "no pending LDs\n");
-                goto out_unlock;
+                return;
         }
 
         /*
@@ -958,7 +908,7 @@ static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
          */
         if (!chan->idle) {
                 chan_dbg(chan, "DMA controller still busy\n");
-                goto out_unlock;
+                return;
         }
 
         /*
@@ -996,9 +946,6 @@ static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
 
         dma_start(chan);
         chan->idle = false;
-
-out_unlock:
-        spin_unlock_irqrestore(&chan->desc_lock, flags);
 }
 
 /**
@@ -1008,7 +955,11 @@ out_unlock:
 static void fsl_dma_memcpy_issue_pending(struct dma_chan *dchan)
 {
         struct fsldma_chan *chan = to_fsl_chan(dchan);
+        unsigned long flags;
+
+        spin_lock_irqsave(&chan->desc_lock, flags);
         fsl_chan_xfer_ld_queue(chan);
+        spin_unlock_irqrestore(&chan->desc_lock, flags);
 }
 
 /**
@@ -1109,20 +1060,53 @@ static irqreturn_t fsldma_chan_irq(int irq, void *data)
 static void dma_do_tasklet(unsigned long data)
 {
         struct fsldma_chan *chan = (struct fsldma_chan *)data;
+        struct fsl_desc_sw *desc, *_desc;
+        LIST_HEAD(ld_cleanup);
         unsigned long flags;
 
         chan_dbg(chan, "tasklet entry\n");
 
-        /* run all callbacks, free all used descriptors */
-        fsl_chan_ld_cleanup(chan);
-
-        /* the channel is now idle */
         spin_lock_irqsave(&chan->desc_lock, flags);
+
+        /* update the cookie if we have some descriptors to cleanup */
+        if (!list_empty(&chan->ld_running)) {
+                dma_cookie_t cookie;
+
+                desc = to_fsl_desc(chan->ld_running.prev);
+                cookie = desc->async_tx.cookie;
+
+                chan->completed_cookie = cookie;
+                chan_dbg(chan, "completed_cookie=%d\n", cookie);
+        }
+
+        /*
+         * move the descriptors to a temporary list so we can drop the lock
+         * during the entire cleanup operation
+         */
+        list_splice_tail_init(&chan->ld_running, &ld_cleanup);
+
+        /* the hardware is now idle and ready for more */
         chan->idle = true;
-        spin_unlock_irqrestore(&chan->desc_lock, flags);
 
-        /* start any pending transactions automatically */
+        /*
+         * Start any pending transactions automatically
+         *
+         * In the ideal case, we keep the DMA controller busy while we go
+         * ahead and free the descriptors below.
+         */
         fsl_chan_xfer_ld_queue(chan);
+        spin_unlock_irqrestore(&chan->desc_lock, flags);
+
+        /* Run the callback for each descriptor, in order */
+        list_for_each_entry_safe(desc, _desc, &ld_cleanup, node) {
+
+                /* Remove from the list of transactions */
+                list_del(&desc->node);
+
+                /* Run all cleanup for this descriptor */
+                fsldma_cleanup_descriptor(chan, desc);
+        }
+
         chan_dbg(chan, "tasklet exit\n");
 }