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Commit 63fe23c3 authored by Russell King's avatar Russell King
Browse files

dmaengine: sa11x0-dma: fix DMA residue support 



The semantics now implemented are:

- If the cookie has completed successfully, the residue will be zero.
- If the cookie is in progress or the channel is paused, it will be the
  number of bytes yet to be transferred. [*]
- If the cookie is queued, it will be the number of bytes in the
  descriptor.

* - where this is the number of bytes yet to be transferred to/from
  RAM.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 571fa740

drivers/dma/sa11x0-dma.c

+29 −16
Original line number Diff line number Diff line
@@ -416,27 +416,47 @@ static enum dma_status sa11x0_dma_tx_status(struct dma_chan *chan, 
	struct sa11x0_dma_chan *c = to_sa11x0_dma_chan(chan);

	struct sa11x0_dma_dev *d = to_sa11x0_dma(chan->device);

	struct sa11x0_dma_phy *p;

	struct sa11x0_dma_desc *txd;

	struct virt_dma_desc *vd;

	unsigned long flags;

	enum dma_status ret;

	size_t bytes = 0;



	ret = dma_cookie_status(&c->vc.chan, cookie, state);

	if (ret == DMA_SUCCESS)

		return ret;



	if (!state)

		return c->status;



	spin_lock_irqsave(&c->vc.lock, flags);

	p = c->phy;

	ret = c->status;

	if (p) {

		dma_addr_t addr = sa11x0_dma_pos(p);



		dev_vdbg(d->slave.dev, "tx_status: addr:%x\n", addr);

	/*

	 * If the cookie is on our issue queue, then the residue is

	 * its total size.

	 */

	vd = vchan_find_desc(&c->vc, cookie);

	if (vd) {

		state->residue = container_of(vd, struct sa11x0_dma_desc, vd)->size;

	} else if (!p) {

		state->residue = 0;

	} else {

		struct sa11x0_dma_desc *txd;

		size_t bytes = 0;



		if (p->txd_done && p->txd_done->vd.tx.cookie == cookie)

			txd = p->txd_done;

		else if (p->txd_load && p->txd_load->vd.tx.cookie == cookie)

			txd = p->txd_load;

		else

			txd = NULL;



		ret = c->status;

		if (txd) {

			dma_addr_t addr = sa11x0_dma_pos(p);

			unsigned i;



			dev_vdbg(d->slave.dev, "tx_status: addr:%x\n", addr);



			for (i = 0; i < txd->sglen; i++) {

				dev_vdbg(d->slave.dev, "tx_status: [%u] %x+%x\n",

					i, txd->sg[i].addr, txd->sg[i].len);
@@ -459,18 +479,11 @@ static enum dma_status sa11x0_dma_tx_status(struct dma_chan *chan, 
				bytes += txd->sg[i].len;

			}

		}

		if (txd != p->txd_load && p->txd_load)

			bytes += p->txd_load->size;

	}

	list_for_each_entry(txd, &c->vc.desc_issued, vd.node) {

		bytes += txd->size;

		state->residue = bytes;

	}

	spin_unlock_irqrestore(&c->vc.lock, flags);



	if (state)

		state->residue = bytes;



	dev_vdbg(d->slave.dev, "tx_status: bytes 0x%zx\n", bytes);

	dev_vdbg(d->slave.dev, "tx_status: bytes 0x%zx\n", state->residue);



	return ret;

}