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Commit cecd87da authored by Linus Walleij's avatar Linus Walleij Committed by Dan Williams
Browse files

DMAENGINE: COH 901 318 rename confusing vars 



This fixes up the code with a lot of comments that make it readable,
rename things with opaque names like "data" into something more
appropriate, and remove some very confusing BUG() statements.

Signed-off-by: default avatarLinus Walleij <linus.walleij@stericsson.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 220bf991

drivers/dma/coh901318.c

+65 −38
Original line number Diff line number Diff line
@@ -37,7 +37,7 @@ struct coh901318_desc { 
	struct list_head node;

	struct scatterlist *sg;

	unsigned int sg_len;

	struct coh901318_lli *data;

	struct coh901318_lli *lli;

	enum dma_data_direction dir;

	unsigned long flags;

};
@@ -283,7 +283,7 @@ static int coh901318_start(struct coh901318_chan *cohc) 
}



static int coh901318_prep_linked_list(struct coh901318_chan *cohc,

				      struct coh901318_lli *data)

				      struct coh901318_lli *lli)

{

	int channel = cohc->id;

	void __iomem *virtbase = cohc->base->virtbase;
@@ -292,18 +292,18 @@ static int coh901318_prep_linked_list(struct coh901318_chan *cohc, 
		     COH901318_CX_STAT_SPACING*channel) &

	       COH901318_CX_STAT_ACTIVE);



	writel(data->src_addr,

	writel(lli->src_addr,

	       virtbase + COH901318_CX_SRC_ADDR +

	       COH901318_CX_SRC_ADDR_SPACING * channel);



	writel(data->dst_addr, virtbase +

	writel(lli->dst_addr, virtbase +

	       COH901318_CX_DST_ADDR +

	       COH901318_CX_DST_ADDR_SPACING * channel);



	writel(data->link_addr, virtbase + COH901318_CX_LNK_ADDR +

	writel(lli->link_addr, virtbase + COH901318_CX_LNK_ADDR +

	       COH901318_CX_LNK_ADDR_SPACING * channel);



	writel(data->control, virtbase + COH901318_CX_CTRL +

	writel(lli->control, virtbase + COH901318_CX_CTRL +

	       COH901318_CX_CTRL_SPACING * channel);



	return 0;
@@ -565,29 +565,30 @@ static int coh901318_config(struct coh901318_chan *cohc, 
 */

static struct coh901318_desc *coh901318_queue_start(struct coh901318_chan *cohc)

{

	struct coh901318_desc *cohd_que;

	struct coh901318_desc *cohd;



	/* start queued jobs, if any

	/*

	 * start queued jobs, if any

	 * TODO: transmit all queued jobs in one go

	 */

	cohd_que = coh901318_first_queued(cohc);

	cohd = coh901318_first_queued(cohc);



	if (cohd_que != NULL) {

	if (cohd != NULL) {

		/* Remove from queue */

		coh901318_desc_remove(cohd_que);

		coh901318_desc_remove(cohd);

		/* initiate DMA job */

		cohc->busy = 1;



		coh901318_desc_submit(cohc, cohd_que);

		coh901318_desc_submit(cohc, cohd);



		coh901318_prep_linked_list(cohc, cohd_que->data);

		coh901318_prep_linked_list(cohc, cohd->lli);



		/* start dma job */

		/* start dma job on this channel */

		coh901318_start(cohc);



	}



	return cohd_que;

	return cohd;

}



/*
@@ -622,7 +623,7 @@ static void dma_tasklet(unsigned long data) 
	cohc->completed = cohd_fin->desc.cookie;



	/* release the lli allocation and remove the descriptor */

	coh901318_lli_free(&cohc->base->pool, &cohd_fin->data);

	coh901318_lli_free(&cohc->base->pool, &cohd_fin->lli);



	/* return desc to free-list */

	coh901318_desc_remove(cohd_fin);
@@ -666,23 +667,44 @@ static void dma_tasklet(unsigned long data) 
/* called from interrupt context */

static void dma_tc_handle(struct coh901318_chan *cohc)

{

	BUG_ON(!cohc->allocated && (list_empty(&cohc->active) ||

				    list_empty(&cohc->queue)));



	if (!cohc->allocated)

	/*

	 * If the channel is not allocated, then we shouldn't have

	 * any TC interrupts on it.

	 */

	if (!cohc->allocated) {

		dev_err(COHC_2_DEV(cohc), "spurious interrupt from "

			"unallocated channel\n");

		return;

	}



	spin_lock(&cohc->lock);



	/*

	 * When we reach this point, at least one queue item

	 * should have been moved over from cohc->queue to

	 * cohc->active and run to completion, that is why we're

	 * getting a terminal count interrupt is it not?

	 * If you get this BUG() the most probable cause is that

	 * the individual nodes in the lli chain have IRQ enabled,

	 * so check your platform config for lli chain ctrl.

	 */

	BUG_ON(list_empty(&cohc->active));



	cohc->nbr_active_done++;



	/*

	 * This attempt to take a job from cohc->queue, put it

	 * into cohc->active and start it.

	 */

	if (coh901318_queue_start(cohc) == NULL)

		cohc->busy = 0;



	BUG_ON(list_empty(&cohc->active));



	spin_unlock(&cohc->lock);



	/*

	 * This tasklet will remove items from cohc->active

	 * and thus terminates them.

	 */

	if (cohc_chan_conf(cohc)->priority_high)

		tasklet_hi_schedule(&cohc->tasklet);

	else
@@ -870,7 +892,7 @@ static struct dma_async_tx_descriptor * 
coh901318_prep_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,

		      size_t size, unsigned long flags)

{

	struct coh901318_lli *data;

	struct coh901318_lli *lli;

	struct coh901318_desc *cohd;

	unsigned long flg;

	struct coh901318_chan *cohc = to_coh901318_chan(chan);
@@ -892,23 +914,23 @@ coh901318_prep_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, 
	if ((lli_len << MAX_DMA_PACKET_SIZE_SHIFT) < size)

		lli_len++;



	data = coh901318_lli_alloc(&cohc->base->pool, lli_len);

	lli = coh901318_lli_alloc(&cohc->base->pool, lli_len);



	if (data == NULL)

	if (lli == NULL)

		goto err;



	ret = coh901318_lli_fill_memcpy(

		&cohc->base->pool, data, src, size, dest,

		&cohc->base->pool, lli, src, size, dest,

		cohc_chan_param(cohc)->ctrl_lli_chained,

		ctrl_last);

	if (ret)

		goto err;



	COH_DBG(coh901318_list_print(cohc, data));

	COH_DBG(coh901318_list_print(cohc, lli));



	/* Pick a descriptor to handle this transfer */

	cohd = coh901318_desc_get(cohc);

	cohd->data = data;

	cohd->lli = lli;

	cohd->flags = flags;

	cohd->desc.tx_submit = coh901318_tx_submit;
@@ -926,7 +948,7 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, 
			unsigned long flags)

{

	struct coh901318_chan *cohc = to_coh901318_chan(chan);

	struct coh901318_lli *data;

	struct coh901318_lli *lli;

	struct coh901318_desc *cohd;

	const struct coh901318_params *params;

	struct scatterlist *sg;
@@ -999,13 +1021,13 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, 
	}



	pr_debug("Allocate %d lli:s for this transfer\n", len);

	data = coh901318_lli_alloc(&cohc->base->pool, len);

	lli = coh901318_lli_alloc(&cohc->base->pool, len);



	if (data == NULL)

	if (lli == NULL)

		goto err_dma_alloc;



	/* initiate allocated data list */

	ret = coh901318_lli_fill_sg(&cohc->base->pool, data, sgl, sg_len,

	/* initiate allocated lli list */

	ret = coh901318_lli_fill_sg(&cohc->base->pool, lli, sgl, sg_len,

				    cohc_dev_addr(cohc),

				    ctrl_chained,

				    ctrl,
@@ -1014,14 +1036,14 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, 
	if (ret)

		goto err_lli_fill;



	COH_DBG(coh901318_list_print(cohc, data));

	COH_DBG(coh901318_list_print(cohc, lli));



	/* Pick a descriptor to handle this transfer */

	cohd = coh901318_desc_get(cohc);

	cohd->dir = direction;

	cohd->flags = flags;

	cohd->desc.tx_submit = coh901318_tx_submit;

	cohd->data = data;

	cohd->lli = lli;



	spin_unlock_irqrestore(&cohc->lock, flg);
@@ -1065,7 +1087,12 @@ coh901318_issue_pending(struct dma_chan *chan) 


	spin_lock_irqsave(&cohc->lock, flags);



	/* Busy means that pending jobs are already being processed */

	/*

	 * Busy means that pending jobs are already being processed,

	 * and then there is no point in starting the queue: the

	 * terminal count interrupt on the channel will take the next

	 * job on the queue and execute it anyway.

	 */

	if (!cohc->busy)

		coh901318_queue_start(cohc);
@@ -1099,7 +1126,7 @@ coh901318_terminate_all(struct dma_chan *chan) 


	while ((cohd = coh901318_first_active_get(cohc))) {

		/* release the lli allocation*/

		coh901318_lli_free(&cohc->base->pool, &cohd->data);

		coh901318_lli_free(&cohc->base->pool, &cohd->lli);



		/* return desc to free-list */

		coh901318_desc_remove(cohd);
@@ -1108,7 +1135,7 @@ coh901318_terminate_all(struct dma_chan *chan) 


	while ((cohd = coh901318_first_queued(cohc))) {

		/* release the lli allocation*/

		coh901318_lli_free(&cohc->base->pool, &cohd->data);

		coh901318_lli_free(&cohc->base->pool, &cohd->lli);



		/* return desc to free-list */

		coh901318_desc_remove(cohd);