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Commit 84c8447c authored by Linus Walleij's avatar Linus Walleij Committed by Dan Williams
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DMAENGINE: COH 901 318 fix bytesleft 



This makes the function to get the number of bytes left in the
ongoing DMA transaction actually work: the old code did not take
neither lli:s nor queued jobs into account. Also fix a missing
spinlock while we're at it.

Signed-off-by: default avatarLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent cecd87da

drivers/dma/coh901318.c

+88 −8
Original line number Diff line number Diff line
@@ -408,25 +408,100 @@ coh901318_first_queued(struct coh901318_chan *cohc) 
	return d;

}



static inline u32 coh901318_get_bytes_in_lli(struct coh901318_lli *in_lli)

{

	struct coh901318_lli *lli = in_lli;

	u32 bytes = 0;



	while (lli) {

		bytes += lli->control & COH901318_CX_CTRL_TC_VALUE_MASK;

		lli = lli->virt_link_addr;

	}

	return bytes;

}



/*

 * DMA start/stop controls

 * Get the number of bytes left to transfer on this channel,

 * it is unwise to call this before stopping the channel for

 * absolute measures, but for a rough guess you can still call

 * it.

 */

u32 coh901318_get_bytes_left(struct dma_chan *chan)

{

	unsigned long flags;

	u32 ret;

	struct coh901318_chan *cohc = to_coh901318_chan(chan);

	struct coh901318_desc *cohd;

	struct list_head *pos;

	unsigned long flags;

	u32 left = 0;

	int i = 0;



	spin_lock_irqsave(&cohc->lock, flags);



	/* Read transfer count value */

	ret = readl(cohc->base->virtbase +

		    COH901318_CX_CTRL+COH901318_CX_CTRL_SPACING *

		    cohc->id) & COH901318_CX_CTRL_TC_VALUE_MASK;

	/*

	 * If there are many queued jobs, we iterate and add the

	 * size of them all. We take a special look on the first

	 * job though, since it is probably active.

	 */

	list_for_each(pos, &cohc->active) {

		/*

		 * The first job in the list will be working on the

		 * hardware. The job can be stopped but still active,

		 * so that the transfer counter is somewhere inside

		 * the buffer.

		 */

		cohd = list_entry(pos, struct coh901318_desc, node);



		if (i == 0) {

			struct coh901318_lli *lli;

			dma_addr_t ladd;



			/* Read current transfer count value */

			left = readl(cohc->base->virtbase +

				     COH901318_CX_CTRL +

				     COH901318_CX_CTRL_SPACING * cohc->id) &

				COH901318_CX_CTRL_TC_VALUE_MASK;



			/* See if the transfer is linked... */

			ladd = readl(cohc->base->virtbase +

				     COH901318_CX_LNK_ADDR +

				     COH901318_CX_LNK_ADDR_SPACING *

				     cohc->id) &

				~COH901318_CX_LNK_LINK_IMMEDIATE;

			/* Single transaction */

			if (!ladd)

				continue;



			/*

			 * Linked transaction, follow the lli, find the

			 * currently processing lli, and proceed to the next

			 */

			lli = cohd->lli;

			while (lli && lli->link_addr != ladd)

				lli = lli->virt_link_addr;



			if (lli)

				lli = lli->virt_link_addr;



			/*

			 * Follow remaining lli links around to count the total

			 * number of bytes left

			 */

			left += coh901318_get_bytes_in_lli(lli);

		} else {

			left += coh901318_get_bytes_in_lli(cohd->lli);

		}

		i++;

	}



	/* Also count bytes in the queued jobs */

	list_for_each(pos, &cohc->queue) {

		cohd = list_entry(pos, struct coh901318_desc, node);

		left += coh901318_get_bytes_in_lli(cohd->lli);

	}



	spin_unlock_irqrestore(&cohc->lock, flags);



	return ret;

	return left;

}

EXPORT_SYMBOL(coh901318_get_bytes_left);
@@ -831,6 +906,7 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id) 
static int coh901318_alloc_chan_resources(struct dma_chan *chan)

{

	struct coh901318_chan	*cohc = to_coh901318_chan(chan);

	unsigned long flags;



	dev_vdbg(COHC_2_DEV(cohc), "[%s] DMA channel %d\n",

		 __func__, cohc->id);
@@ -838,11 +914,15 @@ static int coh901318_alloc_chan_resources(struct dma_chan *chan) 
	if (chan->client_count > 1)

		return -EBUSY;



	spin_lock_irqsave(&cohc->lock, flags);



	coh901318_config(cohc, NULL);



	cohc->allocated = 1;

	cohc->completed = chan->cookie = 1;



	spin_unlock_irqrestore(&cohc->lock, flags);



	return 1;

}