diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/dma/fsldma.c | 108 |
1 files changed, 46 insertions, 62 deletions
diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index 526579df603..d300de456c9 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"); } |