fsldma: fix infinite loop on multi-descriptor DMA chain completion

[karo-tx-linux.git] / drivers / dma / fsldma.c

diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index da8a8ed9e411008d68e14820444695176caa9318..7313a1ae5f833e44c8f559cb35475b27f18c338b 100644 (file)
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c
@@ -313,8 +313,8 @@ static void fsl_chan_toggle_ext_start(struct fsl_dma_chan *fsl_chan, int enable)
 
 static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
 {
-       struct fsl_desc_sw *desc = tx_to_fsl_desc(tx);
        struct fsl_dma_chan *fsl_chan = to_fsl_chan(tx->chan);
+       struct fsl_desc_sw *desc;
        unsigned long flags;
        dma_cookie_t cookie;
 
@@ -322,14 +322,17 @@ static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx)
        spin_lock_irqsave(&fsl_chan->desc_lock, flags);
 
        cookie = fsl_chan->common.cookie;
-       cookie++;
-       if (cookie < 0)
-               cookie = 1;
-       desc->async_tx.cookie = cookie;
-       fsl_chan->common.cookie = desc->async_tx.cookie;
+       list_for_each_entry(desc, &tx->tx_list, node) {
+               cookie++;
+               if (cookie < 0)
+                       cookie = 1;
 
-       append_ld_queue(fsl_chan, desc);
-       list_splice_init(&desc->async_tx.tx_list, fsl_chan->ld_queue.prev);
+               desc->async_tx.cookie = cookie;
+       }
+
+       fsl_chan->common.cookie = cookie;
+       append_ld_queue(fsl_chan, tx_to_fsl_desc(tx));
+       list_splice_init(&tx->tx_list, fsl_chan->ld_queue.prev);
 
        spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 
@@ -598,15 +601,16 @@ static void fsl_chan_xfer_ld_queue(struct fsl_dma_chan *fsl_chan)
        dma_addr_t next_dest_addr;
        unsigned long flags;
 
+       spin_lock_irqsave(&fsl_chan->desc_lock, flags);
+
        if (!dma_is_idle(fsl_chan))
-               return;
+               goto out_unlock;
 
        dma_halt(fsl_chan);
 
        /* If there are some link descriptors
         * not transfered in queue. We need to start it.
         */
-       spin_lock_irqsave(&fsl_chan->desc_lock, flags);
 
        /* Find the first un-transfer desciptor */
        for (ld_node = fsl_chan->ld_queue.next;
@@ -617,8 +621,6 @@ static void fsl_chan_xfer_ld_queue(struct fsl_dma_chan *fsl_chan)
                                fsl_chan->common.cookie) == DMA_SUCCESS);
                ld_node = ld_node->next);
 
-       spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
-
        if (ld_node != &fsl_chan->ld_queue) {
                /* Get the ld start address from ld_queue */
                next_dest_addr = to_fsl_desc(ld_node)->async_tx.phys;
@@ -630,6 +632,9 @@ static void fsl_chan_xfer_ld_queue(struct fsl_dma_chan *fsl_chan)
                set_cdar(fsl_chan, 0);
                set_ndar(fsl_chan, 0);
        }
+
+out_unlock:
+       spin_unlock_irqrestore(&fsl_chan->desc_lock, flags);
 }
 
 /**
@@ -830,7 +835,7 @@ static int __devinit fsl_dma_chan_probe(struct fsl_dma_device *fdev,
                        new_fsl_chan->reg.end - new_fsl_chan->reg.start + 1);
 
        new_fsl_chan->id = ((new_fsl_chan->reg.start - 0x100) & 0xfff) >> 7;
-       if (new_fsl_chan->id > FSL_DMA_MAX_CHANS_PER_DEVICE) {
+       if (new_fsl_chan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) {
                dev_err(fdev->dev, "There is no %d channel!\n",
                                new_fsl_chan->id);
                err = -EINVAL;