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dmaengine: PL08x: split the pend_list in two

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Our behaviour wasn't correct; issue_pending is supposed to be called
before any submitted descriptors are available for processing by the
DMA engine.  Split the pend_list in two, one for submitted descriptors
and another list for issued descriptors.

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 13:10:36 +01:00
parent eab82533c9
commit ea1605612c
1 changed files with 28 additions and 13 deletions
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39
drivers/dma/amba-pl08x.c
View file

@ -217,6 +217,7 @@ 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
* @issued_list: issued transactions for this channel
* @done_list: list of completed transactions
* @at: active transaction on this channel
* @lock: a lock for this channel data
@ -235,6 +236,7 @@ struct pl08x_dma_chan {
const struct pl08x_channel_data *cd;
struct dma_slave_config cfg;
struct list_head pend_list;
struct list_head issued_list;
struct list_head done_list;
struct pl08x_txd *at;
spinlock_t lock;
@ -362,7 +364,7 @@ static void pl08x_start_next_txd(struct pl08x_dma_chan *plchan)
struct pl08x_txd *txd;
u32 val;
txd = list_first_entry(&plchan->pend_list, struct pl08x_txd, node);
txd = list_first_entry(&plchan->issued_list, struct pl08x_txd, node);
list_del(&txd->node);
plchan->at = txd;
@ -525,6 +527,15 @@ static u32 pl08x_getbytes_chan(struct pl08x_dma_chan *plchan)
}
/* Sum up all queued transactions */
if (!list_empty(&plchan->issued_list)) {
struct pl08x_txd *txdi;
list_for_each_entry(txdi, &plchan->issued_list, node) {
struct pl08x_sg *dsg;
list_for_each_entry(dsg, &txd->dsg_list, node)
bytes += dsg->len;
}
}
if (!list_empty(&plchan->pend_list)) {
struct pl08x_txd *txdi;
list_for_each_entry(txdi, &plchan->pend_list, node) {
@ -991,16 +1002,17 @@ static void pl08x_free_txd(struct pl08x_driver_data *pl08x,
static void pl08x_free_txd_list(struct pl08x_driver_data *pl08x,
struct pl08x_dma_chan *plchan)
{
struct pl08x_txd *txdi = NULL;
struct pl08x_txd *next;
LIST_HEAD(head);
struct pl08x_txd *txd;
if (!list_empty(&plchan->pend_list)) {
list_for_each_entry_safe(txdi,
next, &plchan->pend_list, node) {
list_splice_tail_init(&plchan->issued_list, &head);
list_splice_tail_init(&plchan->pend_list, &head);
while (!list_empty(&head)) {
txd = list_first_entry(&head, struct pl08x_txd, node);
pl08x_release_mux(plchan);
list_del(&txdi->node);
pl08x_free_txd(pl08x, txdi);
}
list_del(&txd->node);
pl08x_free_txd(pl08x, txd);
}
}
@ -1269,6 +1281,8 @@ static void pl08x_issue_pending(struct dma_chan *chan)
unsigned long flags;
spin_lock_irqsave(&plchan->lock, flags);
list_splice_tail_init(&plchan->pend_list, &plchan->issued_list);
/* Something is already active, or we're waiting for a channel... */
if (plchan->at || plchan->state == PL08X_CHAN_WAITING) {
spin_unlock_irqrestore(&plchan->lock, flags);
@ -1276,7 +1290,7 @@ static void pl08x_issue_pending(struct dma_chan *chan)
}
/* Take the first element in the queue and execute it */
if (!list_empty(&plchan->pend_list)) {
if (!list_empty(&plchan->issued_list)) {
plchan->state = PL08X_CHAN_RUNNING;
pl08x_start_next_txd(plchan);
}
@ -1658,9 +1672,9 @@ static void pl08x_tasklet(unsigned long data)
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)) {
if (!list_empty(&plchan->issued_list)) {
pl08x_start_next_txd(plchan);
} else if (plchan->phychan_hold) {
} else if (!list_empty(&plchan->pend_list) || plchan->phychan_hold) {
/*
* This channel is still in use - we have a new txd being
* prepared and will soon be queued. Don't give up the
@ -1841,6 +1855,7 @@ 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->issued_list);
INIT_LIST_HEAD(&chan->done_list);
tasklet_init(&chan->tasklet, pl08x_tasklet,
(unsigned long) chan);