Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: (66 commits)
  avr32: at32ap700x: fix typo in DMA master configuration
  dmaengine/dmatest: Pass timeout via module params
  dma: let IMX_DMA depend on IMX_HAVE_DMA_V1 instead of an explicit list of SoCs
  fsldma: make halt behave nicely on all supported controllers
  fsldma: reduce locking during descriptor cleanup
  fsldma: support async_tx dependencies and automatic unmapping
  fsldma: fix controller lockups
  fsldma: minor codingstyle and consistency fixes
  fsldma: improve link descriptor debugging
  fsldma: use channel name in printk output
  fsldma: move related helper functions near each other
  dmatest: fix automatic buffer unmap type
  drivers, pch_dma: Fix warning when CONFIG_PM=n.
  dmaengine/dw_dmac fix: use readl & writel instead of __raw_readl & __raw_writel
  avr32: at32ap700x: Specify DMA Flow Controller, Src and Dst msize
  dw_dmac: Setting Default Burst length for transfers as 16.
  dw_dmac: Allow src/dst msize & flow controller to be configured at runtime
  dw_dmac: Changing type of src_master and dest_master to u8.
  dw_dmac: Pass Channel Priority from platform_data
  dw_dmac: Pass Channel Allocation Order from platform_data
  ...

1 files changed, 301 insertions, 250 deletions

diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index e3854a8f0de0..6b396759e7f5 100644
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c
@@ -37,35 +37,16 @@
 
 #include "fsldma.h"
 
-static const char msg_ld_oom[] = "No free memory for link descriptor\n";
+#define chan_dbg(chan, fmt, arg...)                                     \
+        dev_dbg(chan->dev, "%s: " fmt, chan->name, ##arg)
+#define chan_err(chan, fmt, arg...)                                     \
+        dev_err(chan->dev, "%s: " fmt, chan->name, ##arg)
 
-static void dma_init(struct fsldma_chan *chan)
-{
-        /* Reset the channel */
-        DMA_OUT(chan, &chan->regs->mr, 0, 32);
+static const char msg_ld_oom[] = "No free memory for link descriptor";
 
-        switch (chan->feature & FSL_DMA_IP_MASK) {
-        case FSL_DMA_IP_85XX:
-                /* Set the channel to below modes:
-                 * EIE - Error interrupt enable
-                 * EOSIE - End of segments interrupt enable (basic mode)
-                 * EOLNIE - End of links interrupt enable
-                 * BWC - Bandwidth sharing among channels
-                 */
-                DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_BWC
-                                | FSL_DMA_MR_EIE | FSL_DMA_MR_EOLNIE
-                                | FSL_DMA_MR_EOSIE, 32);
-                break;
-        case FSL_DMA_IP_83XX:
-                /* Set the channel to below modes:
-                 * EOTIE - End-of-transfer interrupt enable
-                 * PRC_RM - PCI read multiple
-                 */
-                DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_EOTIE
-                                | FSL_DMA_MR_PRC_RM, 32);
-                break;
-        }
-}
+/*
+ * Register Helpers
+ */
 
 static void set_sr(struct fsldma_chan *chan, u32 val)
 {
@@ -77,14 +58,38 @@ static u32 get_sr(struct fsldma_chan *chan)
         return DMA_IN(chan, &chan->regs->sr, 32);
 }
 
+static void set_cdar(struct fsldma_chan *chan, dma_addr_t addr)
+{
+        DMA_OUT(chan, &chan->regs->cdar, addr | FSL_DMA_SNEN, 64);
+}
+
+static dma_addr_t get_cdar(struct fsldma_chan *chan)
+{
+        return DMA_IN(chan, &chan->regs->cdar, 64) & ~FSL_DMA_SNEN;
+}
+
+static u32 get_bcr(struct fsldma_chan *chan)
+{
+        return DMA_IN(chan, &chan->regs->bcr, 32);
+}
+
+/*
+ * Descriptor Helpers
+ */
+
 static void set_desc_cnt(struct fsldma_chan *chan,
                                 struct fsl_dma_ld_hw *hw, u32 count)
 {
         hw->count = CPU_TO_DMA(chan, count, 32);
 }
 
+static u32 get_desc_cnt(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
+{
+        return DMA_TO_CPU(chan, desc->hw.count, 32);
+}
+
 static void set_desc_src(struct fsldma_chan *chan,
-                                struct fsl_dma_ld_hw *hw, dma_addr_t src)
+                         struct fsl_dma_ld_hw *hw, dma_addr_t src)
 {
         u64 snoop_bits;
 
@@ -93,8 +98,18 @@ static void set_desc_src(struct fsldma_chan *chan,
         hw->src_addr = CPU_TO_DMA(chan, snoop_bits | src, 64);
 }
 
+static dma_addr_t get_desc_src(struct fsldma_chan *chan,
+                               struct fsl_desc_sw *desc)
+{
+        u64 snoop_bits;
+
+        snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
+                ? ((u64)FSL_DMA_SATR_SREADTYPE_SNOOP_READ << 32) : 0;
+        return DMA_TO_CPU(chan, desc->hw.src_addr, 64) & ~snoop_bits;
+}
+
 static void set_desc_dst(struct fsldma_chan *chan,
-                                struct fsl_dma_ld_hw *hw, dma_addr_t dst)
+                         struct fsl_dma_ld_hw *hw, dma_addr_t dst)
 {
         u64 snoop_bits;
 
@@ -103,8 +118,18 @@ static void set_desc_dst(struct fsldma_chan *chan,
         hw->dst_addr = CPU_TO_DMA(chan, snoop_bits | dst, 64);
 }
 
+static dma_addr_t get_desc_dst(struct fsldma_chan *chan,
+                               struct fsl_desc_sw *desc)
+{
+        u64 snoop_bits;
+
+        snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX)
+                ? ((u64)FSL_DMA_DATR_DWRITETYPE_SNOOP_WRITE << 32) : 0;
+        return DMA_TO_CPU(chan, desc->hw.dst_addr, 64) & ~snoop_bits;
+}
+
 static void set_desc_next(struct fsldma_chan *chan,
-                                struct fsl_dma_ld_hw *hw, dma_addr_t next)
+                          struct fsl_dma_ld_hw *hw, dma_addr_t next)
 {
         u64 snoop_bits;
 
@@ -113,24 +138,46 @@ static void set_desc_next(struct fsldma_chan *chan,
         hw->next_ln_addr = CPU_TO_DMA(chan, snoop_bits | next, 64);
 }
 
-static void set_cdar(struct fsldma_chan *chan, dma_addr_t addr)
+static void set_ld_eol(struct fsldma_chan *chan, struct fsl_desc_sw *desc)
 {
-        DMA_OUT(chan, &chan->regs->cdar, addr | FSL_DMA_SNEN, 64);
-}
+        u64 snoop_bits;
 
-static dma_addr_t get_cdar(struct fsldma_chan *chan)
-{
-        return DMA_IN(chan, &chan->regs->cdar, 64) & ~FSL_DMA_SNEN;
-}
+        snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
+                ? FSL_DMA_SNEN : 0;
 
-static dma_addr_t get_ndar(struct fsldma_chan *chan)
-{
-        return DMA_IN(chan, &chan->regs->ndar, 64);
+        desc->hw.next_ln_addr = CPU_TO_DMA(chan,
+                DMA_TO_CPU(chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL
+                        | snoop_bits, 64);
 }
 
-static u32 get_bcr(struct fsldma_chan *chan)
+/*
+ * DMA Engine Hardware Control Helpers
+ */
+
+static void dma_init(struct fsldma_chan *chan)
 {
-        return DMA_IN(chan, &chan->regs->bcr, 32);
+        /* Reset the channel */
+        DMA_OUT(chan, &chan->regs->mr, 0, 32);
+
+        switch (chan->feature & FSL_DMA_IP_MASK) {
+        case FSL_DMA_IP_85XX:
+                /* Set the channel to below modes:
+                 * EIE - Error interrupt enable
+                 * EOLNIE - End of links interrupt enable
+                 * BWC - Bandwidth sharing among channels
+                 */
+                DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_BWC
+                                | FSL_DMA_MR_EIE | FSL_DMA_MR_EOLNIE, 32);
+                break;
+        case FSL_DMA_IP_83XX:
+                /* Set the channel to below modes:
+                 * EOTIE - End-of-transfer interrupt enable
+                 * PRC_RM - PCI read multiple
+                 */
+                DMA_OUT(chan, &chan->regs->mr, FSL_DMA_MR_EOTIE
+                                | FSL_DMA_MR_PRC_RM, 32);
+                break;
+        }
 }
 
 static int dma_is_idle(struct fsldma_chan *chan)
@@ -139,25 +186,32 @@ static int dma_is_idle(struct fsldma_chan *chan)
         return (!(sr & FSL_DMA_SR_CB)) || (sr & FSL_DMA_SR_CH);
 }
 
+/*
+ * Start the DMA controller
+ *
+ * Preconditions:
+ * - the CDAR register must point to the start descriptor
+ * - the MRn[CS] bit must be cleared
+ */
 static void dma_start(struct fsldma_chan *chan)
 {
         u32 mode;
 
         mode = DMA_IN(chan, &chan->regs->mr, 32);
 
-        if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
-                if (chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
-                        DMA_OUT(chan, &chan->regs->bcr, 0, 32);
-                        mode |= FSL_DMA_MR_EMP_EN;
-                } else {
-                        mode &= ~FSL_DMA_MR_EMP_EN;
-                }
+        if (chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
+                DMA_OUT(chan, &chan->regs->bcr, 0, 32);
+                mode |= FSL_DMA_MR_EMP_EN;
+        } else {
+                mode &= ~FSL_DMA_MR_EMP_EN;
         }
 
-        if (chan->feature & FSL_DMA_CHAN_START_EXT)
+        if (chan->feature & FSL_DMA_CHAN_START_EXT) {
                 mode |= FSL_DMA_MR_EMS_EN;
-        else
+        } else {
+                mode &= ~FSL_DMA_MR_EMS_EN;
                 mode |= FSL_DMA_MR_CS;
+        }
 
         DMA_OUT(chan, &chan->regs->mr, mode, 32);
 }
@@ -167,13 +221,26 @@ static void dma_halt(struct fsldma_chan *chan)
         u32 mode;
         int i;
 
+        /* read the mode register */
         mode = DMA_IN(chan, &chan->regs->mr, 32);
-        mode |= FSL_DMA_MR_CA;
-        DMA_OUT(chan, &chan->regs->mr, mode, 32);
 
-        mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN | FSL_DMA_MR_CA);
+        /*
+         * The 85xx controller supports channel abort, which will stop
+         * the current transfer. On 83xx, this bit is the transfer error
+         * mask bit, which should not be changed.
+         */
+        if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
+                mode |= FSL_DMA_MR_CA;
+                DMA_OUT(chan, &chan->regs->mr, mode, 32);
+
+                mode &= ~FSL_DMA_MR_CA;
+        }
+
+        /* stop the DMA controller */
+        mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN);
         DMA_OUT(chan, &chan->regs->mr, mode, 32);
 
+        /* wait for the DMA controller to become idle */
         for (i = 0; i < 100; i++) {
                 if (dma_is_idle(chan))
                         return;
@@ -182,20 +249,7 @@ static void dma_halt(struct fsldma_chan *chan)
         }
 
         if (!dma_is_idle(chan))
-                dev_err(chan->dev, "DMA halt timeout!\n");
-}
-
-static void set_ld_eol(struct fsldma_chan *chan,
-                        struct fsl_desc_sw *desc)
-{
-        u64 snoop_bits;
-
-        snoop_bits = ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_83XX)
-                ? FSL_DMA_SNEN : 0;
-
-        desc->hw.next_ln_addr = CPU_TO_DMA(chan,
-                DMA_TO_CPU(chan, desc->hw.next_ln_addr, 64) | FSL_DMA_EOL
-                        | snoop_bits, 64);
+                chan_err(chan, "DMA halt timeout!\n");
 }
 
 /**
@@ -321,8 +375,7 @@ 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)
+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);
 
@@ -363,8 +416,8 @@ static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
         cookie = chan->common.cookie;
         list_for_each_entry(child, &desc->tx_list, node) {
                 cookie++;
-                if (cookie < 0)
-                        cookie = 1;
+                if (cookie < DMA_MIN_COOKIE)
+                        cookie = DMA_MIN_COOKIE;
 
                 child->async_tx.cookie = cookie;
         }
@@ -385,15 +438,14 @@ static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
  *
  * Return - The descriptor allocated. NULL for failed.
  */
-static struct fsl_desc_sw *fsl_dma_alloc_descriptor(
-                                        struct fsldma_chan *chan)
+static struct fsl_desc_sw *fsl_dma_alloc_descriptor(struct fsldma_chan *chan)
 {
         struct fsl_desc_sw *desc;
         dma_addr_t pdesc;
 
         desc = dma_pool_alloc(chan->desc_pool, GFP_ATOMIC, &pdesc);
         if (!desc) {
-                dev_dbg(chan->dev, "out of memory for link desc\n");
+                chan_dbg(chan, "out of memory for link descriptor\n");
                 return NULL;
         }
 
@@ -403,10 +455,13 @@ static struct fsl_desc_sw *fsl_dma_alloc_descriptor(
         desc->async_tx.tx_submit = fsl_dma_tx_submit;
         desc->async_tx.phys = pdesc;
 
+#ifdef FSL_DMA_LD_DEBUG
+        chan_dbg(chan, "LD %p allocated\n", desc);
+#endif
+
         return desc;
 }
 
-
 /**
  * fsl_dma_alloc_chan_resources - Allocate resources for DMA channel.
  * @chan : Freescale DMA channel
@@ -427,13 +482,11 @@ static int fsl_dma_alloc_chan_resources(struct dma_chan *dchan)
          * 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,
+        chan->desc_pool = dma_pool_create(chan->name, chan->dev,
                                           sizeof(struct fsl_desc_sw),
                                           __alignof__(struct fsl_desc_sw), 0);
         if (!chan->desc_pool) {
-                dev_err(chan->dev, "unable to allocate channel %d "
-                                   "descriptor pool\n", chan->id);
+                chan_err(chan, "unable to allocate descriptor pool\n");
                 return -ENOMEM;
         }
 
@@ -455,6 +508,9 @@ static void fsldma_free_desc_list(struct fsldma_chan *chan,
 
         list_for_each_entry_safe(desc, _desc, list, node) {
                 list_del(&desc->node);
+#ifdef FSL_DMA_LD_DEBUG
+                chan_dbg(chan, "LD %p free\n", desc);
+#endif
                 dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
         }
 }
@@ -466,6 +522,9 @@ static void fsldma_free_desc_list_reverse(struct fsldma_chan *chan,
 
         list_for_each_entry_safe_reverse(desc, _desc, list, node) {
                 list_del(&desc->node);
+#ifdef FSL_DMA_LD_DEBUG
+                chan_dbg(chan, "LD %p free\n", desc);
+#endif
                 dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
         }
 }
@@ -479,7 +538,7 @@ static void fsl_dma_free_chan_resources(struct dma_chan *dchan)
         struct fsldma_chan *chan = to_fsl_chan(dchan);
         unsigned long flags;
 
-        dev_dbg(chan->dev, "Free all channel resources.\n");
+        chan_dbg(chan, "free all channel resources\n");
         spin_lock_irqsave(&chan->desc_lock, flags);
         fsldma_free_desc_list(chan, &chan->ld_pending);
         fsldma_free_desc_list(chan, &chan->ld_running);
@@ -502,7 +561,7 @@ fsl_dma_prep_interrupt(struct dma_chan *dchan, unsigned long flags)
 
         new = fsl_dma_alloc_descriptor(chan);
         if (!new) {
-                dev_err(chan->dev, msg_ld_oom);
+                chan_err(chan, "%s\n", msg_ld_oom);
                 return NULL;
         }
 
@@ -512,14 +571,15 @@ fsl_dma_prep_interrupt(struct dma_chan *dchan, unsigned long flags)
         /* Insert the link descriptor to the LD ring */
         list_add_tail(&new->node, &new->tx_list);
 
-        /* Set End-of-link to the last link descriptor of new list*/
+        /* Set End-of-link to the last link descriptor of new list */
         set_ld_eol(chan, new);
 
         return &new->async_tx;
 }
 
-static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy(
-        struct dma_chan *dchan, dma_addr_t dma_dst, dma_addr_t dma_src,
+static struct dma_async_tx_descriptor *
+fsl_dma_prep_memcpy(struct dma_chan *dchan,
+        dma_addr_t dma_dst, dma_addr_t dma_src,
         size_t len, unsigned long flags)
 {
         struct fsldma_chan *chan;
@@ -539,12 +599,9 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy(
                 /* Allocate the link descriptor from DMA pool */
                 new = fsl_dma_alloc_descriptor(chan);
                 if (!new) {
-                        dev_err(chan->dev, msg_ld_oom);
+                        chan_err(chan, "%s\n", msg_ld_oom);
                         goto fail;
                 }
-#ifdef FSL_DMA_LD_DEBUG
-                dev_dbg(chan->dev, "new link desc alloc %p\n", new);
-#endif
 
                 copy = min(len, (size_t)FSL_DMA_BCR_MAX_CNT);
 
@@ -572,7 +629,7 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_memcpy(
         new->async_tx.flags = flags; /* client is in control of this ack */
         new->async_tx.cookie = -EBUSY;
 
-        /* Set End-of-link to the last link descriptor of new list*/
+        /* Set End-of-link to the last link descriptor of new list */
         set_ld_eol(chan, new);
 
         return &first->async_tx;
@@ -627,12 +684,9 @@ static struct dma_async_tx_descriptor *fsl_dma_prep_sg(struct dma_chan *dchan,
                 /* allocate and populate the descriptor */
                 new = fsl_dma_alloc_descriptor(chan);
                 if (!new) {
-                        dev_err(chan->dev, msg_ld_oom);
+                        chan_err(chan, "%s\n", msg_ld_oom);
                         goto fail;
                 }
-#ifdef FSL_DMA_LD_DEBUG
-                dev_dbg(chan->dev, "new link desc alloc %p\n", new);
-#endif
 
                 set_desc_cnt(chan, &new->hw, len);
                 set_desc_src(chan, &new->hw, src);
@@ -744,14 +798,15 @@ static int fsl_dma_device_control(struct dma_chan *dchan,
 
         switch (cmd) {
         case DMA_TERMINATE_ALL:
+                spin_lock_irqsave(&chan->desc_lock, flags);
+
                 /* Halt the DMA engine */
                 dma_halt(chan);
 
-                spin_lock_irqsave(&chan->desc_lock, flags);
-
                 /* Remove and free all of the descriptors in the LD queue */
                 fsldma_free_desc_list(chan, &chan->ld_pending);
                 fsldma_free_desc_list(chan, &chan->ld_running);
+                chan->idle = true;
 
                 spin_unlock_irqrestore(&chan->desc_lock, flags);
                 return 0;
@@ -789,140 +844,87 @@ static int fsl_dma_device_control(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 *desc;
-        unsigned long flags;
-        dma_cookie_t cookie;
-
-        spin_lock_irqsave(&chan->desc_lock, flags);
-
-        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;
-                if (unlikely(cookie < DMA_MIN_COOKIE))
-                        cookie = DMA_MAX_COOKIE;
-        }
-
-        chan->completed_cookie = cookie;
-
-out_unlock:
-        spin_unlock_irqrestore(&chan->desc_lock, flags);
-}
-
-/**
- * fsldma_desc_status - Check the status of a descriptor
+ * fsldma_cleanup_descriptor - cleanup and free a single link 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);
-}
-
-/**
- * fsl_chan_ld_cleanup - Clean up link descriptors
- * @chan : Freescale DMA channel
+ * @desc: descriptor to cleanup and free
  *
- * This function clean up the ld_queue of DMA channel.
+ * This function is used on a descriptor which has been executed by the DMA
+ * controller. It will run any callbacks, submit any dependencies, and then
+ * free the descriptor.
  */
-static void fsl_chan_ld_cleanup(struct fsldma_chan *chan)
+static void fsldma_cleanup_descriptor(struct fsldma_chan *chan,
+                                      struct fsl_desc_sw *desc)
 {
-        struct fsl_desc_sw *desc, *_desc;
-        unsigned long flags;
-
-        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_running, node) {
-                dma_async_tx_callback callback;
-                void *callback_param;
-
-                if (fsldma_desc_status(chan, desc) == DMA_IN_PROGRESS)
-                        break;
+        struct dma_async_tx_descriptor *txd = &desc->async_tx;
+        struct device *dev = chan->common.device->dev;
+        dma_addr_t src = get_desc_src(chan, desc);
+        dma_addr_t dst = get_desc_dst(chan, desc);
+        u32 len = get_desc_cnt(chan, desc);
+
+        /* Run the link descriptor callback function */
+        if (txd->callback) {
+#ifdef FSL_DMA_LD_DEBUG
+                chan_dbg(chan, "LD %p callback\n", desc);
+#endif
+                txd->callback(txd->callback_param);
+        }
 
-                /* Remove from the list of running transactions */
-                list_del(&desc->node);
+        /* Run any dependencies */
+        dma_run_dependencies(txd);
 
-                /* 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, "LD %p callback\n", desc);
-                        callback(callback_param);
-                        spin_lock_irqsave(&chan->desc_lock, flags);
-                }
+        /* Unmap the dst buffer, if requested */
+        if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
+                if (txd->flags & DMA_COMPL_DEST_UNMAP_SINGLE)
+                        dma_unmap_single(dev, dst, len, DMA_FROM_DEVICE);
+                else
+                        dma_unmap_page(dev, dst, len, DMA_FROM_DEVICE);
+        }
 
-                /* Run any dependencies, then free the descriptor */
-                dma_run_dependencies(&desc->async_tx);
-                dma_pool_free(chan->desc_pool, desc, desc->async_tx.phys);
+        /* Unmap the src buffer, if requested */
+        if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
+                if (txd->flags & DMA_COMPL_SRC_UNMAP_SINGLE)
+                        dma_unmap_single(dev, src, len, DMA_TO_DEVICE);
+                else
+                        dma_unmap_page(dev, src, len, DMA_TO_DEVICE);
         }
 
-        spin_unlock_irqrestore(&chan->desc_lock, flags);
+#ifdef FSL_DMA_LD_DEBUG
+        chan_dbg(chan, "LD %p free\n", desc);
+#endif
+        dma_pool_free(chan->desc_pool, desc, txd->phys);
 }
 
 /**
  * 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.
+ * 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
          * 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;
+                chan_dbg(chan, "no pending LDs\n");
+                return;
         }
 
         /*
-         * 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
+         * The DMA controller is not idle, which means that the interrupt
+         * handler will start any queued transactions when it runs after
+         * this transaction finishes
          */
-        if (!dma_is_idle(chan)) {
-                dev_dbg(chan->dev, "DMA controller still busy\n");
-                goto out_unlock;
+        if (!chan->idle) {
+                chan_dbg(chan, "DMA controller still busy\n");
+                return;
         }
 
         /*
-         * 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 which have not been
          * transferred, we need to start the controller
          */
@@ -931,18 +933,32 @@ static void fsl_chan_xfer_ld_queue(struct fsldma_chan *chan)
          * Move all elements from the queue of pending transactions
          * onto the list of running transactions
          */
+        chan_dbg(chan, "idle, starting controller\n");
         desc = list_first_entry(&chan->ld_pending, struct fsl_desc_sw, node);
         list_splice_tail_init(&chan->ld_pending, &chan->ld_running);
 
         /*
+         * The 85xx DMA controller doesn't clear the channel start bit
+         * automatically at the end of a transfer. Therefore we must clear
+         * it in software before starting the transfer.
+         */
+        if ((chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
+                u32 mode;
+
+                mode = DMA_IN(chan, &chan->regs->mr, 32);
+                mode &= ~FSL_DMA_MR_CS;
+                DMA_OUT(chan, &chan->regs->mr, mode, 32);
+        }
+
+        /*
          * Program the descriptor's address into the DMA controller,
          * then start the DMA transaction
          */
         set_cdar(chan, desc->async_tx.phys);
-        dma_start(chan);
+        get_cdar(chan);
 
-out_unlock:
-        spin_unlock_irqrestore(&chan->desc_lock, flags);
+        dma_start(chan);
+        chan->idle = false;
 }
 
 /**
@@ -952,7 +968,11 @@ 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);
 }
 
 /**
@@ -964,16 +984,18 @@ static enum dma_status fsl_tx_status(struct dma_chan *dchan,
                                         struct dma_tx_state *txstate)
 {
         struct fsldma_chan *chan = to_fsl_chan(dchan);
-        dma_cookie_t last_used;
         dma_cookie_t last_complete;
+        dma_cookie_t last_used;
+        unsigned long flags;
 
-        fsl_chan_ld_cleanup(chan);
+        spin_lock_irqsave(&chan->desc_lock, flags);
 
-        last_used = dchan->cookie;
         last_complete = chan->completed_cookie;
+        last_used = dchan->cookie;
 
-        dma_set_tx_state(txstate, last_complete, last_used, 0);
+        spin_unlock_irqrestore(&chan->desc_lock, flags);
 
+        dma_set_tx_state(txstate, last_complete, last_used, 0);
         return dma_async_is_complete(cookie, last_complete, last_used);
 }
 
@@ -984,21 +1006,20 @@ static enum dma_status fsl_tx_status(struct dma_chan *dchan,
 static irqreturn_t fsldma_chan_irq(int irq, void *data)
 {
         struct fsldma_chan *chan = data;
-        int update_cookie = 0;
-        int xfer_ld_q = 0;
         u32 stat;
 
         /* save and clear the status register */
         stat = get_sr(chan);
         set_sr(chan, stat);
-        dev_dbg(chan->dev, "irq: channel %d, stat = 0x%x\n", chan->id, stat);
+        chan_dbg(chan, "irq: stat = 0x%x\n", stat);
 
+        /* check that this was really our device */
         stat &= ~(FSL_DMA_SR_CB | FSL_DMA_SR_CH);
         if (!stat)
                 return IRQ_NONE;
 
         if (stat & FSL_DMA_SR_TE)
-                dev_err(chan->dev, "Transfer Error!\n");
+                chan_err(chan, "Transfer Error!\n");
 
         /*
          * Programming Error
@@ -1006,29 +1027,10 @@ static irqreturn_t fsldma_chan_irq(int irq, void *data)
          * triger a PE interrupt.
          */
         if (stat & FSL_DMA_SR_PE) {
-                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
-                         * next uncompleted transfer.
-                         */
-                        update_cookie = 1;
-                        xfer_ld_q = 1;
-                }
+                chan_dbg(chan, "irq: Programming Error INT\n");
                 stat &= ~FSL_DMA_SR_PE;
-        }
-
-        /*
-         * If the link descriptor segment transfer finishes,
-         * we will recycle the used descriptor.
-         */
-        if (stat & FSL_DMA_SR_EOSI) {
-                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;
+                if (get_bcr(chan) != 0)
+                        chan_err(chan, "Programming Error!\n");
         }
 
         /*
@@ -1036,10 +1038,8 @@ static irqreturn_t fsldma_chan_irq(int irq, void *data)
          * and start the next transfer if it exist.
          */
         if (stat & FSL_DMA_SR_EOCDI) {
-                dev_dbg(chan->dev, "irq: End-of-Chain link INT\n");
+                chan_dbg(chan, "irq: End-of-Chain link INT\n");
                 stat &= ~FSL_DMA_SR_EOCDI;
-                update_cookie = 1;
-                xfer_ld_q = 1;
         }
 
         /*
@@ -1048,27 +1048,79 @@ static irqreturn_t fsldma_chan_irq(int irq, void *data)
          * prepare next transfer.
          */
         if (stat & FSL_DMA_SR_EOLNI) {
-                dev_dbg(chan->dev, "irq: End-of-link INT\n");
+                chan_dbg(chan, "irq: End-of-link INT\n");
                 stat &= ~FSL_DMA_SR_EOLNI;
-                xfer_ld_q = 1;
         }
 
-        if (update_cookie)
-                fsl_dma_update_completed_cookie(chan);
-        if (xfer_ld_q)
-                fsl_chan_xfer_ld_queue(chan);
+        /* check that the DMA controller is really idle */
+        if (!dma_is_idle(chan))
+                chan_err(chan, "irq: controller not idle!\n");
+
+        /* check that we handled all of the bits */
         if (stat)
-                dev_dbg(chan->dev, "irq: unhandled sr 0x%02x\n", stat);
+                chan_err(chan, "irq: unhandled sr 0x%08x\n", stat);
 
-        dev_dbg(chan->dev, "irq: Exit\n");
+        /*
+         * Schedule the tasklet to handle all cleanup of the current
+         * transaction. It will start a new transaction if there is
+         * one pending.
+         */
         tasklet_schedule(&chan->tasklet);
+        chan_dbg(chan, "irq: Exit\n");
         return IRQ_HANDLED;
 }
 
 static void dma_do_tasklet(unsigned long data)
 {
         struct fsldma_chan *chan = (struct fsldma_chan *)data;
-        fsl_chan_ld_cleanup(chan);
+        struct fsl_desc_sw *desc, *_desc;
+        LIST_HEAD(ld_cleanup);
+        unsigned long flags;
+
+        chan_dbg(chan, "tasklet entry\n");
+
+        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;
+
+        /*
+         * 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");
 }
 
 static irqreturn_t fsldma_ctrl_irq(int irq, void *data)
@@ -1116,7 +1168,7 @@ static void fsldma_free_irqs(struct fsldma_device *fdev)
         for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
                 chan = fdev->chan[i];
                 if (chan && chan->irq != NO_IRQ) {
-                        dev_dbg(fdev->dev, "free channel %d IRQ\n", chan->id);
+                        chan_dbg(chan, "free per-channel IRQ\n");
                         free_irq(chan->irq, chan);
                 }
         }
@@ -1143,19 +1195,16 @@ static int fsldma_request_irqs(struct fsldma_device *fdev)
                         continue;
 
                 if (chan->irq == NO_IRQ) {
-                        dev_err(fdev->dev, "no interrupts property defined for "
-                                           "DMA channel %d. Please fix your "
-                                           "device tree\n", chan->id);
+                        chan_err(chan, "interrupts property missing in device tree\n");
                         ret = -ENODEV;
                         goto out_unwind;
                 }
 
-                dev_dbg(fdev->dev, "request channel %d IRQ\n", chan->id);
+                chan_dbg(chan, "request per-channel IRQ\n");
                 ret = request_irq(chan->irq, fsldma_chan_irq, IRQF_SHARED,
                                   "fsldma-chan", chan);
                 if (ret) {
-                        dev_err(fdev->dev, "unable to request IRQ for DMA "
-                                           "channel %d\n", chan->id);
+                        chan_err(chan, "unable to request per-channel IRQ\n");
                         goto out_unwind;
                 }
         }
@@ -1230,6 +1279,7 @@ static int __devinit fsl_dma_chan_probe(struct fsldma_device *fdev,
 
         fdev->chan[chan->id] = chan;
         tasklet_init(&chan->tasklet, dma_do_tasklet, (unsigned long)chan);
+        snprintf(chan->name, sizeof(chan->name), "chan%d", chan->id);
 
         /* Initialize the channel */
         dma_init(chan);
@@ -1250,6 +1300,7 @@ static int __devinit fsl_dma_chan_probe(struct fsldma_device *fdev,
         spin_lock_init(&chan->desc_lock);
         INIT_LIST_HEAD(&chan->ld_pending);
         INIT_LIST_HEAD(&chan->ld_running);
+        chan->idle = true;
 
         chan->common.device = &fdev->common;