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Commit ea160561 authored by Russell King's avatar Russell King
Browse files

dmaengine: PL08x: split the pend_list in two 



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: default avatarLinus Walleij <linus.walleij@linaro.org>
Tested-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent eab82533

drivers/dma/amba-pl08x.c

+28 −13
Original line number Diff line number Diff line
@@ -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);