fsldma: major cleanups and fixes
authorIra Snyder <iws@ovro.caltech.edu>
Wed, 6 Jan 2010 13:34:06 +0000 (13:34 +0000)
committerDan Williams <dan.j.williams@intel.com>
Tue, 2 Feb 2010 21:51:42 +0000 (14:51 -0700)
Fix locking. Use two queues in the driver, one for pending transacions, and
one for transactions which are actually running on the hardware. Call
dma_run_dependencies() on descriptor cleanup so that the async_tx API works
correctly.

There are a number of places throughout the code where lists of descriptors
are freed in a loop. Create functions to handle this, and use them instead
of open-coding the loop each time.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
drivers/dma/fsldma.c
drivers/dma/fsldma.h

index 7b5f88cb495bba3397e57e37f4c3bf6385d50ee0..19011c20390b535b2620c6eb9f1979b28d332236 100644 (file)
@@ -61,7 +61,6 @@ static void dma_init(struct fsldma_chan *chan)
                                | FSL_DMA_MR_PRC_RM, 32);
                break;
        }
-
 }
 
 static void set_sr(struct fsldma_chan *chan, u32 val)
@@ -120,11 +119,6 @@ static dma_addr_t get_cdar(struct fsldma_chan *chan)
        return DMA_IN(chan, &chan->regs->cdar, 64) & ~FSL_DMA_SNEN;
 }
 
-static void set_ndar(struct fsldma_chan *chan, dma_addr_t addr)
-{
-       DMA_OUT(chan, &chan->regs->ndar, addr, 64);
-}
-
 static dma_addr_t get_ndar(struct fsldma_chan *chan)
 {
        return DMA_IN(chan, &chan->regs->ndar, 64);
@@ -178,11 +172,12 @@ static void dma_halt(struct fsldma_chan *chan)
 
        for (i = 0; i < 100; i++) {
                if (dma_is_idle(chan))
-                       break;
+                       return;
+
                udelay(10);
        }
 
-       if (i >= 100 && !dma_is_idle(chan))
+       if (!dma_is_idle(chan))
                dev_err(chan->dev, "DMA halt timeout!\n");
 }
 
@@ -199,27 +194,6 @@ static void set_ld_eol(struct fsldma_chan *chan,
                        | snoop_bits, 64);
 }
 
-static void append_ld_queue(struct fsldma_chan *chan,
-               struct fsl_desc_sw *new_desc)
-{
-       struct fsl_desc_sw *queue_tail = to_fsl_desc(chan->ld_queue.prev);
-
-       if (list_empty(&chan->ld_queue))
-               return;
-
-       /* Link to the new descriptor physical address and
-        * Enable End-of-segment interrupt for
-        * the last link descriptor.
-        * (the previous node's next link descriptor)
-        *
-        * For FSL_DMA_IP_83xx, the snoop enable bit need be set.
-        */
-       queue_tail->hw.next_ln_addr = CPU_TO_DMA(chan,
-                       new_desc->async_tx.phys | FSL_DMA_EOSIE |
-                       (((chan->feature & FSL_DMA_IP_MASK)
-                               == FSL_DMA_IP_83XX) ? FSL_DMA_SNEN : 0), 64);
-}
-
 /**
  * fsl_chan_set_src_loop_size - Set source address hold transfer size
  * @chan : Freescale DMA channel
@@ -343,6 +317,31 @@ static void fsl_chan_toggle_ext_start(struct fsldma_chan *chan, int enable)
                chan->feature &= ~FSL_DMA_CHAN_START_EXT;
 }
 
+static void append_ld_queue(struct fsldma_chan *chan,
+                           struct fsl_desc_sw *desc)
+{
+       struct fsl_desc_sw *tail = to_fsl_desc(chan->ld_pending.prev);
+
+       if (list_empty(&chan->ld_pending))
+               goto out_splice;
+
+       /*
+        * Add the hardware descriptor to the chain of hardware descriptors
+        * that already exists in memory.
+        *
+        * This will un-set the EOL bit of the existing transaction, and the
+        * last link in this transaction will become the EOL descriptor.
+        */
+       set_desc_next(chan, &tail->hw, desc->async_tx.phys);
+
+       /*
+        * Add the software descriptor and all children to the list
+        * of pending transactions
+        */
+out_splice:
+       list_splice_tail_init(&desc->tx_list, &chan->ld_pending);
+}
+
 static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
 {
        struct fsldma_chan *chan = to_fsl_chan(tx->chan);
@@ -351,9 +350,12 @@ static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
        unsigned long flags;
        dma_cookie_t cookie;
 
-       /* cookie increment and adding to ld_queue must be atomic */
        spin_lock_irqsave(&chan->desc_lock, flags);
 
+       /*
+        * assign cookies to all of the software descriptors
+        * that make up this transaction
+        */
        cookie = chan->common.cookie;
        list_for_each_entry(child, &desc->tx_list, node) {
                cookie++;
@@ -364,8 +366,9 @@ static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
        }
 
        chan->common.cookie = cookie;
+
+       /* put this transaction onto the tail of the pending queue */
        append_ld_queue(chan, desc);
-       list_splice_init(&desc->tx_list, chan->ld_queue.prev);
 
        spin_unlock_irqrestore(&chan->desc_lock, flags);
 
@@ -381,20 +384,22 @@ static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
 static struct fsl_desc_sw *fsl_dma_alloc_descriptor(
                                        struct fsldma_chan *chan)
 {
+       struct fsl_desc_sw *desc;
        dma_addr_t pdesc;
-       struct fsl_desc_sw *desc_sw;
-
-       desc_sw = dma_pool_alloc(chan->desc_pool, GFP_ATOMIC, &pdesc);
-       if (desc_sw) {
-               memset(desc_sw, 0, sizeof(struct fsl_desc_sw));
-               INIT_LIST_HEAD(&desc_sw->tx_list);
-               dma_async_tx_descriptor_init(&desc_sw->async_tx,
-                                               &chan->common);
-               desc_sw->async_tx.tx_submit = fsl_dma_tx_submit;
-               desc_sw->async_tx.phys = pdesc;
+
+       desc = dma_pool_alloc(chan->desc_pool, GFP_ATOMIC, &pdesc);
+       if (!desc) {
+               dev_dbg(chan->dev, "out of memory for link desc\n");
+               return NULL;
        }
 
-       return desc_sw;
+       memset(desc, 0, sizeof(*desc));
+       INIT_LIST_HEAD(&desc->tx_list);
+       dma_async_tx_descriptor_init(&desc->async_tx, &chan->common);
+       desc->async_tx.tx_submit = fsl_dma_tx_submit;
+       desc->async_tx.phys = pdesc;
+
+       return desc;
 }
 
 
@@ -414,21 +419,53 @@ static int fsl_dma_alloc_chan_resources(struct dma_chan *dchan)
        if (chan->desc_pool)
                return 1;
 
-       /* We need the descriptor to be aligned to 32bytes
+       /*
+        * We need the descriptor to be aligned to 32bytes
         * for meeting FSL DMA specification requirement.
         */
        chan->desc_pool = dma_pool_create("fsl_dma_engine_desc_pool",
-                       chan->dev, sizeof(struct fsl_desc_sw),
-                       32, 0);
+                                         chan->dev,
+                                         sizeof(struct fsl_desc_sw),
+                                         __alignof__(struct fsl_desc_sw), 0);
        if (!chan->desc_pool) {
-               dev_err(chan->dev, "No memory for channel %d "
-                       "descriptor dma pool.\n", chan->id);
-               return 0;
+               dev_err(chan->dev, "unable to allocate channel %d "
+                                  "descriptor pool\n", chan->id);
+               return -ENOMEM;
        }
 
+       /* there is at least one descriptor free to be allocated */
        return 1;
 }
 
+/**
+ * fsldma_free_desc_list - Free all descriptors in a queue
+ * @chan: Freescae DMA channel
+ * @list: the list to free
+ *
+ * LOCKING: must hold chan->desc_lock
+ */
+static void fsldma_free_desc_list(struct fsldma_chan *chan,
+                                 struct list_head *list)
+{
+       struct fsl_desc_sw *desc, *_desc;
+
+       list_for_each_entry_safe(desc, _desc, list, node) {
+               list_del(&desc->node);
+               dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
+       }
+}
+
+static void fsldma_free_desc_list_reverse(struct fsldma_chan *chan,
+                                         struct list_head *list)
+{
+       struct fsl_desc_sw *desc, *_desc;
+
+       list_for_each_entry_safe_reverse(desc, _desc, list, node) {
+               list_del(&desc->node);
+               dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
+       }
+}
+
 /**
  * fsl_dma_free_chan_resources - Free all resources of the channel.
  * @chan : Freescale DMA channel
@@ -436,23 +473,15 @@ static int fsl_dma_alloc_chan_resources(struct dma_chan *dchan)
 static void fsl_dma_free_chan_resources(struct dma_chan *dchan)
 {
        struct fsldma_chan *chan = to_fsl_chan(dchan);
-       struct fsl_desc_sw *desc, *_desc;
        unsigned long flags;
 
        dev_dbg(chan->dev, "Free all channel resources.\n");
        spin_lock_irqsave(&chan->desc_lock, flags);
-       list_for_each_entry_safe(desc, _desc, &chan->ld_queue, node) {
-#ifdef FSL_DMA_LD_DEBUG
-               dev_dbg(chan->dev,
-                               "LD %p will be released.\n", desc);
-#endif
-               list_del(&desc->node);
-               /* free link descriptor */
-               dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
-       }
+       fsldma_free_desc_list(chan, &chan->ld_pending);
+       fsldma_free_desc_list(chan, &chan->ld_running);
        spin_unlock_irqrestore(&chan->desc_lock, flags);
-       dma_pool_destroy(chan->desc_pool);
 
+       dma_pool_destroy(chan->desc_pool);
        chan->desc_pool = NULL;
 }
 
@@ -491,7 +520,6 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy(
 {
        struct fsldma_chan *chan;
        struct fsl_desc_sw *first = NULL, *prev = NULL, *new;
-       struct list_head *list;
        size_t copy;
 
        if (!dchan)
@@ -550,12 +578,7 @@ fail:
        if (!first)
                return NULL;
 
-       list = &first->tx_list;
-       list_for_each_entry_safe_reverse(new, prev, list, node) {
-               list_del(&new->node);
-               dma_pool_free(chan->desc_pool, new, new->async_tx.phys);
-       }
-
+       fsldma_free_desc_list_reverse(chan, &first->tx_list);
        return NULL;
 }
 
@@ -578,7 +601,6 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_slave_sg(
        struct fsldma_chan *chan;
        struct fsl_desc_sw *first = NULL, *prev = NULL, *new = NULL;
        struct fsl_dma_slave *slave;
-       struct list_head *tx_list;
        size_t copy;
 
        int i;
@@ -748,19 +770,13 @@ fail:
         *
         * We're re-using variables for the loop, oh well
         */
-       tx_list = &first->tx_list;
-       list_for_each_entry_safe_reverse(new, prev, tx_list, node) {
-               list_del_init(&new->node);
-               dma_pool_free(chan->desc_pool, new, new->async_tx.phys);
-       }
-
+       fsldma_free_desc_list_reverse(chan, &first->tx_list);
        return NULL;
 }
 
 static void fsl_dma_device_terminate_all(struct dma_chan *dchan)
 {
        struct fsldma_chan *chan;
-       struct fsl_desc_sw *desc, *tmp;
        unsigned long flags;
 
        if (!dchan)
@@ -774,10 +790,8 @@ static void fsl_dma_device_terminate_all(struct dma_chan *dchan)
        spin_lock_irqsave(&chan->desc_lock, flags);
 
        /* Remove and free all of the descriptors in the LD queue */
-       list_for_each_entry_safe(desc, tmp, &chan->ld_queue, node) {
-               list_del(&desc->node);
-               dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
-       }
+       fsldma_free_desc_list(chan, &chan->ld_pending);
+       fsldma_free_desc_list(chan, &chan->ld_running);
 
        spin_unlock_irqrestore(&chan->desc_lock, flags);
 }
@@ -785,31 +799,48 @@ static void fsl_dma_device_terminate_all(struct dma_chan *dchan)
 /**
  * fsl_dma_update_completed_cookie - Update the completed cookie.
  * @chan : Freescale DMA channel
+ *
+ * CONTEXT: hardirq
  */
 static void fsl_dma_update_completed_cookie(struct fsldma_chan *chan)
 {
-       struct fsl_desc_sw *cur_desc, *desc;
-       dma_addr_t ld_phy;
-
-       ld_phy = get_cdar(chan) & FSL_DMA_NLDA_MASK;
+       struct fsl_desc_sw *desc;
+       unsigned long flags;
+       dma_cookie_t cookie;
 
-       if (ld_phy) {
-               cur_desc = NULL;
-               list_for_each_entry(desc, &chan->ld_queue, node)
-                       if (desc->async_tx.phys == ld_phy) {
-                               cur_desc = desc;
-                               break;
-                       }
+       spin_lock_irqsave(&chan->desc_lock, flags);
 
-               if (cur_desc && cur_desc->async_tx.cookie) {
-                       if (dma_is_idle(chan))
-                               chan->completed_cookie =
-                                       cur_desc->async_tx.cookie;
-                       else
-                               chan->completed_cookie =
-                                       cur_desc->async_tx.cookie - 1;
-               }
+       if (list_empty(&chan->ld_running)) {
+               dev_dbg(chan->dev, "no running descriptors\n");
+               goto out_unlock;
        }
+
+       /* Get the last descriptor, update the cookie to that */
+       desc = to_fsl_desc(chan->ld_running.prev);
+       if (dma_is_idle(chan))
+               cookie = desc->async_tx.cookie;
+       else
+               cookie = desc->async_tx.cookie - 1;
+
+       chan->completed_cookie = cookie;
+
+out_unlock:
+       spin_unlock_irqrestore(&chan->desc_lock, flags);
+}
+
+/**
+ * fsldma_desc_status - Check the status of a descriptor
+ * @chan: Freescale DMA channel
+ * @desc: DMA SW descriptor
+ *
+ * This function will return the status of the given descriptor
+ */
+static enum dma_status fsldma_desc_status(struct fsldma_chan *chan,
+                                         struct fsl_desc_sw *desc)
+{
+       return dma_async_is_complete(desc->async_tx.cookie,
+                                    chan->completed_cookie,
+                                    chan->common.cookie);
 }
 
 /**
@@ -817,8 +848,6 @@ static void fsl_dma_update_completed_cookie(struct fsldma_chan *chan)
  * @chan : Freescale DMA channel
  *
  * This function clean up the ld_queue of DMA channel.
- * If 'in_intr' is set, the function will move the link descriptor to
- * the recycle list. Otherwise, free it directly.
  */
 static void fsl_chan_ld_cleanup(struct fsldma_chan *chan)
 {
@@ -827,80 +856,95 @@ static void fsl_chan_ld_cleanup(struct fsldma_chan *chan)
 
        spin_lock_irqsave(&chan->desc_lock, flags);
 
-       dev_dbg(chan->dev, "chan completed_cookie = %d\n",
-                       chan->completed_cookie);
-       list_for_each_entry_safe(desc, _desc, &chan->ld_queue, node) {
+       dev_dbg(chan->dev, "chan completed_cookie = %d\n", chan->completed_cookie);
+       list_for_each_entry_safe(desc, _desc, &chan->ld_running, node) {
                dma_async_tx_callback callback;
                void *callback_param;
 
-               if (dma_async_is_complete(desc->async_tx.cookie,
-                           chan->completed_cookie, chan->common.cookie)
-                               == DMA_IN_PROGRESS)
+               if (fsldma_desc_status(chan, desc) == DMA_IN_PROGRESS)
                        break;
 
-               callback = desc->async_tx.callback;
-               callback_param = desc->async_tx.callback_param;
-
-               /* Remove from ld_queue list */
+               /* Remove from the list of running transactions */
                list_del(&desc->node);
 
-               dev_dbg(chan->dev, "link descriptor %p will be recycle.\n",
-                               desc);
-               dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
-
                /* Run the link descriptor callback function */
+               callback = desc->async_tx.callback;
+               callback_param = desc->async_tx.callback_param;
                if (callback) {
                        spin_unlock_irqrestore(&chan->desc_lock, flags);
-                       dev_dbg(chan->dev, "link descriptor %p callback\n",
-                                       desc);
+                       dev_dbg(chan->dev, "LD %p callback\n", desc);
                        callback(callback_param);
                        spin_lock_irqsave(&chan->desc_lock, flags);
                }
+
+               /* Run any dependencies, then free the descriptor */
+               dma_run_dependencies(&desc->async_tx);
+               dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
        }
+
        spin_unlock_irqrestore(&chan->desc_lock, flags);
 }
 
 /**
- * fsl_chan_xfer_ld_queue - Transfer link descriptors in channel ld_queue.
+ * fsl_chan_xfer_ld_queue - transfer any pending transactions
  * @chan : Freescale DMA channel
+ *
+ * This will make sure that any pending transactions will be run.
+ * If the DMA controller is idle, it will be started. Otherwise,
+ * the DMA controller's interrupt handler will start any pending
+ * transactions when it becomes idle.
  */
 static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
 {
-       struct list_head *ld_node;
-       dma_addr_t next_dst_addr;
+       struct fsl_desc_sw *desc;
        unsigned long flags;
 
        spin_lock_irqsave(&chan->desc_lock, flags);
 
-       if (!dma_is_idle(chan))
+       /*
+        * If the list of pending descriptors is empty, then we
+        * don't need to do any work at all
+        */
+       if (list_empty(&chan->ld_pending)) {
+               dev_dbg(chan->dev, "no pending LDs\n");
                goto out_unlock;
+       }
 
+       /*
+        * The DMA controller is not idle, which means the interrupt
+        * handler will start any queued transactions when it runs
+        * at the end of the current transaction
+        */
+       if (!dma_is_idle(chan)) {
+               dev_dbg(chan->dev, "DMA controller still busy\n");
+               goto out_unlock;
+       }
+
+       /*
+        * TODO:
+        * make sure the dma_halt() function really un-wedges the
+        * controller as much as possible
+        */
        dma_halt(chan);
 
-       /* If there are some link descriptors
-        * not transfered in queue. We need to start it.
+       /*
+        * If there are some link descriptors which have not been
+        * transferred, we need to start the controller
         */
 
-       /* Find the first un-transfer desciptor */
-       for (ld_node = chan->ld_queue.next;
-               (ld_node != &chan->ld_queue)
-                       && (dma_async_is_complete(
-                               to_fsl_desc(ld_node)->async_tx.cookie,
-                               chan->completed_cookie,
-                               chan->common.cookie) == DMA_SUCCESS);
-               ld_node = ld_node->next);
-
-       if (ld_node != &chan->ld_queue) {
-               /* Get the ld start address from ld_queue */
-               next_dst_addr = to_fsl_desc(ld_node)->async_tx.phys;
-               dev_dbg(chan->dev, "xfer LDs staring from 0x%llx\n",
-                               (unsigned long long)next_dst_addr);
-               set_cdar(chan, next_dst_addr);
-               dma_start(chan);
-       } else {
-               set_cdar(chan, 0);
-               set_ndar(chan, 0);
-       }
+       /*
+        * Move all elements from the queue of pending transactions
+        * onto the list of running transactions
+        */
+       desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node);
+       list_splice_tail_init(&chan->ld_pending, &chan->ld_running);
+
+       /*
+        * Program the descriptor's address into the DMA controller,
+        * then start the DMA transaction
+        */
+       set_cdar(chan, desc->async_tx.phys);
+       dma_start(chan);
 
 out_unlock:
        spin_unlock_irqrestore(&chan->desc_lock, flags);
@@ -913,30 +957,6 @@ out_unlock:
 static void fsl_dma_memcpy_issue_pending(struct dma_chan *dchan)
 {
        struct fsldma_chan *chan = to_fsl_chan(dchan);
-
-#ifdef FSL_DMA_LD_DEBUG
-       struct fsl_desc_sw *ld;
-       unsigned long flags;
-
-       spin_lock_irqsave(&chan->desc_lock, flags);
-       if (list_empty(&chan->ld_queue)) {
-               spin_unlock_irqrestore(&chan->desc_lock, flags);
-               return;
-       }
-
-       dev_dbg(chan->dev, "--memcpy issue--\n");
-       list_for_each_entry(ld, &chan->ld_queue, node) {
-               int i;
-               dev_dbg(chan->dev, "Ch %d, LD %08x\n",
-                               chan->id, ld->async_tx.phys);
-               for (i = 0; i < 8; i++)
-                       dev_dbg(chan->dev, "LD offset %d: %08x\n",
-                                       i, *(((u32 *)&ld->hw) + i));
-       }
-       dev_dbg(chan->dev, "----------------\n");
-       spin_unlock_irqrestore(&chan->desc_lock, flags);
-#endif
-
        fsl_chan_xfer_ld_queue(chan);
 }
 
@@ -978,10 +998,10 @@ static irqreturn_t fsldma_chan_irq(int irq, void *data)
        int xfer_ld_q = 0;
        u32 stat;
 
+       /* save and clear the status register */
        stat = get_sr(chan);
-       dev_dbg(chan->dev, "event: channel %d, stat = 0x%x\n",
-                                               chan->id, stat);
-       set_sr(chan, stat);             /* Clear the event register */
+       set_sr(chan, stat);
+       dev_dbg(chan->dev, "irq: channel %d, stat = 0x%x\n", chan->id, stat);
 
        stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH);
        if (!stat)
@@ -990,12 +1010,13 @@ static irqreturn_t fsldma_chan_irq(int irq, void *data)
        if (stat & FSL_DMA_SR_TE)
                dev_err(chan->dev, "Transfer Error!\n");
 
-       /* Programming Error
+       /*
+        * Programming Error
         * The DMA_INTERRUPT async_tx is a NULL transfer, which will
         * triger a PE interrupt.
         */
        if (stat & FSL_DMA_SR_PE) {
-               dev_dbg(chan->dev, "event: Programming Error INT\n");
+               dev_dbg(chan->dev, "irq: Programming Error INT\n");
                if (get_bcr(chan) == 0) {
                        /* BCR register is 0, this is a DMA_INTERRUPT async_tx.
                         * Now, update the completed cookie, and continue the
@@ -1007,34 +1028,37 @@ static irqreturn_t fsldma_chan_irq(int irq, void *data)
                stat &= ~FSL_DMA_SR_PE;
        }
 
-       /* If the link descriptor segment transfer finishes,
+       /*
+        * If the link descriptor segment transfer finishes,
         * we will recycle the used descriptor.
         */
        if (stat & FSL_DMA_SR_EOSI) {
-               dev_dbg(chan->dev, "event: End-of-segments INT\n");
-               dev_dbg(chan->dev, "event: clndar 0x%llx, nlndar 0x%llx\n",
+               dev_dbg(chan->dev, "irq: End-of-segments INT\n");
+               dev_dbg(chan->dev, "irq: clndar 0x%llx, nlndar 0x%llx\n",
                        (unsigned long long)get_cdar(chan),
                        (unsigned long long)get_ndar(chan));
                stat &= ~FSL_DMA_SR_EOSI;
                update_cookie = 1;
        }
 
-       /* For MPC8349, EOCDI event need to update cookie
+       /*
+        * For MPC8349, EOCDI event need to update cookie
         * and start the next transfer if it exist.
         */
        if (stat & FSL_DMA_SR_EOCDI) {
-               dev_dbg(chan->dev, "event: End-of-Chain link INT\n");
+               dev_dbg(chan->dev, "irq: End-of-Chain link INT\n");
                stat &= ~FSL_DMA_SR_EOCDI;
                update_cookie = 1;
                xfer_ld_q = 1;
        }
 
-       /* If it current transfer is the end-of-transfer,
+       /*
+        * If it current transfer is the end-of-transfer,
         * we should clear the Channel Start bit for
         * prepare next transfer.
         */
        if (stat & FSL_DMA_SR_EOLNI) {
-               dev_dbg(chan->dev, "event: End-of-link INT\n");
+               dev_dbg(chan->dev, "irq: End-of-link INT\n");
                stat &= ~FSL_DMA_SR_EOLNI;
                xfer_ld_q = 1;
        }
@@ -1044,10 +1068,9 @@ static irqreturn_t fsldma_chan_irq(int irq, void *data)
        if (xfer_ld_q)
                fsl_chan_xfer_ld_queue(chan);
        if (stat)
-               dev_dbg(chan->dev, "event: unhandled sr 0x%02x\n",
-                                       stat);
+               dev_dbg(chan->dev, "irq: unhandled sr 0x%02x\n", stat);
 
-       dev_dbg(chan->dev, "event: Exit\n");
+       dev_dbg(chan->dev, "irq: Exit\n");
        tasklet_schedule(&chan->tasklet);
        return IRQ_HANDLED;
 }
@@ -1235,7 +1258,8 @@ static int __devinit fsl_dma_chan_probe(struct fsldma_device *fdev,
        }
 
        spin_lock_init(&chan->desc_lock);
-       INIT_LIST_HEAD(&chan->ld_queue);
+       INIT_LIST_HEAD(&chan->ld_pending);
+       INIT_LIST_HEAD(&chan->ld_running);
 
        chan->common.device = &fdev->common;
 
index ea3b19c8708cdd5c29064a78966ed9c01c7d7fef..cb4d6ff5159766baf7dce594dca6fb57e3d28dd2 100644 (file)
@@ -131,7 +131,8 @@ struct fsldma_chan {
        struct fsldma_chan_regs __iomem *regs;
        dma_cookie_t completed_cookie;  /* The maximum cookie completed */
        spinlock_t desc_lock;           /* Descriptor operation lock */
-       struct list_head ld_queue;      /* Link descriptors queue */
+       struct list_head ld_pending;    /* Link descriptors queue */
+       struct list_head ld_running;    /* Link descriptors queue */
        struct dma_chan common;         /* DMA common channel */
        struct dma_pool *desc_pool;     /* Descriptors pool */
        struct device *dev;             /* Channel device */