dmaengine: dw: don't perform DMA when dmaengine_submit is called

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

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 13ac3f240e7963127c713f44f296bd421edf8999..b0972b3869c730229bc91c9829c7ef625cc1ed35 100644 (file)
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -279,6 +279,15 @@ static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
        channel_set_bit(dw, CH_EN, dwc->mask);
 }
 
+static void dwc_dostart_first_queued(struct dw_dma_chan *dwc)
+{
+       if (list_empty(&dwc->queue))
+               return;
+
+       list_move(dwc->queue.next, &dwc->active_list);
+       dwc_dostart(dwc, dwc_first_active(dwc));
+}
+
 /*----------------------------------------------------------------------*/
 
 static void
@@ -335,10 +344,7 @@ static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
         * the completed ones.
         */
        list_splice_init(&dwc->active_list, &list);
-       if (!list_empty(&dwc->queue)) {
-               list_move(dwc->queue.next, &dwc->active_list);
-               dwc_dostart(dwc, dwc_first_active(dwc));
-       }
+       dwc_dostart_first_queued(dwc);
 
        spin_unlock_irqrestore(&dwc->lock, flags);
 
@@ -467,10 +473,7 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
        /* Try to continue after resetting the channel... */
        dwc_chan_disable(dw, dwc);
 
-       if (!list_empty(&dwc->queue)) {
-               list_move(dwc->queue.next, &dwc->active_list);
-               dwc_dostart(dwc, dwc_first_active(dwc));
-       }
+       dwc_dostart_first_queued(dwc);
        spin_unlock_irqrestore(&dwc->lock, flags);
 }
 
@@ -677,17 +680,9 @@ static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
         * possible, perhaps even appending to those already submitted
         * for DMA. But this is hard to do in a race-free manner.
         */
-       if (list_empty(&dwc->active_list)) {
-               dev_vdbg(chan2dev(tx->chan), "%s: started %u\n", __func__,
-                               desc->txd.cookie);
-               list_add_tail(&desc->desc_node, &dwc->active_list);
-               dwc_dostart(dwc, dwc_first_active(dwc));
-       } else {
-               dev_vdbg(chan2dev(tx->chan), "%s: queued %u\n", __func__,
-                               desc->txd.cookie);
 
-               list_add_tail(&desc->desc_node, &dwc->queue);
-       }
+       dev_vdbg(chan2dev(tx->chan), "%s: queued %u\n", __func__, desc->txd.cookie);
+       list_add_tail(&desc->desc_node, &dwc->queue);
 
        spin_unlock_irqrestore(&dwc->lock, flags);
 
@@ -1092,9 +1087,12 @@ dwc_tx_status(struct dma_chan *chan,
 static void dwc_issue_pending(struct dma_chan *chan)
 {
        struct dw_dma_chan      *dwc = to_dw_dma_chan(chan);
+       unsigned long           flags;
 
-       if (!list_empty(&dwc->queue))
-               dwc_scan_descriptors(to_dw_dma(chan->device), dwc);
+       spin_lock_irqsave(&dwc->lock, flags);
+       if (list_empty(&dwc->active_list))
+               dwc_dostart_first_queued(dwc);
+       spin_unlock_irqrestore(&dwc->lock, flags);
 }
 
 static int dwc_alloc_chan_resources(struct dma_chan *chan)
@@ -1545,11 +1543,6 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
        /* Disable BLOCK interrupts as well */
        channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask);
 
-       err = devm_request_irq(chip->dev, chip->irq, dw_dma_interrupt,
-                              IRQF_SHARED, "dw_dmac", dw);
-       if (err)
-               return err;
-
        /* Create a pool of consistent memory blocks for hardware descriptors */
        dw->desc_pool = dmam_pool_create("dw_dmac_desc_pool", chip->dev,
                                         sizeof(struct dw_desc), 4, 0);
@@ -1560,6 +1553,11 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata)
 
        tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw);
 
+       err = request_irq(chip->irq, dw_dma_interrupt, IRQF_SHARED,
+                         "dw_dmac", dw);
+       if (err)
+               return err;
+
        INIT_LIST_HEAD(&dw->dma.channels);
        for (i = 0; i < nr_channels; i++) {
                struct dw_dma_chan      *dwc = &dw->chan[i];
@@ -1664,6 +1662,7 @@ int dw_dma_remove(struct dw_dma_chip *chip)
        dw_dma_off(dw);
        dma_async_device_unregister(&dw->dma);
 
+       free_irq(chip->irq, dw);
        tasklet_kill(&dw->tasklet);
 
        list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels,