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dmaengine: PL08x: convert to a list of completed descriptors 

Convert PL08x to use a list of completed descriptors rather than
merely relying upon a single pointer.  This makes it possible to
schedule the tasklet for other purposes, and makes our behaviour
similar to virt-dma.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2012-05-25 10:51:19 +01:00
parent 5e2479bd0e
commit a936e79313
1 changed files with 20 additions and 10 deletions
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30
drivers/dma/amba-pl08x.c
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@ -219,6 +219,7 @@ enum pl08x_dma_chan_state {
* @cd: channel platform data
* @runtime_addr: address for RX/TX according to the runtime config
* @pend_list: queued transactions pending on this channel
* @done_list: list of completed transactions
* @at: active transaction on this channel
* @lock: a lock for this channel data
* @host: a pointer to the host (internal use)
@ -238,6 +239,7 @@ struct pl08x_dma_chan {
const struct pl08x_channel_data *cd;
struct dma_slave_config cfg;
struct list_head pend_list;
struct list_head done_list;
struct pl08x_txd *at;
spinlock_t lock;
struct pl08x_driver_data *host;
@ -1673,18 +1675,11 @@ static void pl08x_tasklet(unsigned long data)
{
struct pl08x_dma_chan *plchan = (struct pl08x_dma_chan *) data;
struct pl08x_driver_data *pl08x = plchan->host;
struct pl08x_txd *txd;
unsigned long flags;
LIST_HEAD(head);
spin_lock_irqsave(&plchan->lock, flags);
txd = plchan->at;
plchan->at = NULL;
if (txd) {
/* Update last completed */
dma_cookie_complete(&txd->tx);
}
list_splice_tail_init(&plchan->done_list, &head);
/* If a new descriptor is queued, set it up plchan->at is NULL here */
if (!list_empty(&plchan->pend_list)) {
@ -1739,10 +1734,14 @@ static void pl08x_tasklet(unsigned long data)
spin_unlock_irqrestore(&plchan->lock, flags);
if (txd) {
while (!list_empty(&head)) {
struct pl08x_txd *txd = list_first_entry(&head,
struct pl08x_txd, node);
dma_async_tx_callback callback = txd->tx.callback;
void *callback_param = txd->tx.callback_param;
list_del(&txd->node);
/* Don't try to unmap buffers on slave channels */
if (!plchan->slave)
pl08x_unmap_buffers(txd);
@ -1782,6 +1781,7 @@ static irqreturn_t pl08x_irq(int irq, void *dev)
/* Locate physical channel */
struct pl08x_phy_chan *phychan = &pl08x->phy_chans[i];
struct pl08x_dma_chan *plchan = phychan->serving;
struct pl08x_txd *tx;
if (!plchan) {
dev_err(&pl08x->adev->dev,
@ -1790,6 +1790,15 @@ static irqreturn_t pl08x_irq(int irq, void *dev)
continue;
}
spin_lock(&plchan->lock);
tx = plchan->at;
if (tx) {
plchan->at = NULL;
dma_cookie_complete(&tx->tx);
list_add_tail(&tx->node, &plchan->done_list);
}
spin_unlock(&plchan->lock);
/* Schedule tasklet on this channel */
tasklet_schedule(&plchan->tasklet);
mask |= (1 << i);
@ -1856,6 +1865,7 @@ static int pl08x_dma_init_virtual_channels(struct pl08x_driver_data *pl08x,
spin_lock_init(&chan->lock);
INIT_LIST_HEAD(&chan->pend_list);
INIT_LIST_HEAD(&chan->done_list);
tasklet_init(&chan->tasklet, pl08x_tasklet,
(unsigned long) chan);