lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

DMAENGINE: COH 901 318 rename confusing vars

Browse Source 
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: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Linus Walleij
2010-03-04 14:31:47 +01:00
committed by Dan Williams
parent 220bf991b0
commit cecd87da83
1 changed files with 65 additions and 38 deletions
Download Patch File Download Diff File Expand all files Collapse all files

103
drivers/dma/coh901318.c
View File

@@ -37,7 +37,7 @@ struct coh901318_desc {
struct list_head node; struct list_head node;
struct scatterlist *sg; struct scatterlist *sg;
unsigned int sg_len; unsigned int sg_len;
struct coh901318_lli *data; struct coh901318_lli *lli;
enum dma_data_direction dir; enum dma_data_direction dir;
unsigned long flags; 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, static int coh901318_prep_linked_list(struct coh901318_chan *cohc,
struct coh901318_lli *data) struct coh901318_lli *lli)
{ {
int channel = cohc->id; int channel = cohc->id;
void __iomem *virtbase = cohc->base->virtbase; 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_SPACING*channel) &
COH901318_CX_STAT_ACTIVE); COH901318_CX_STAT_ACTIVE);
writel(data->src_addr, writel(lli->src_addr,
virtbase + COH901318_CX_SRC_ADDR + virtbase + COH901318_CX_SRC_ADDR +
COH901318_CX_SRC_ADDR_SPACING * channel); COH901318_CX_SRC_ADDR_SPACING * channel);
writel(data->dst_addr, virtbase + writel(lli->dst_addr, virtbase +
COH901318_CX_DST_ADDR + COH901318_CX_DST_ADDR +
COH901318_CX_DST_ADDR_SPACING * channel); 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); 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); COH901318_CX_CTRL_SPACING * channel);
return 0; 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) 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 * 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 */ /* Remove from queue */
coh901318_desc_remove(cohd_que); coh901318_desc_remove(cohd);
/* initiate DMA job */ /* initiate DMA job */
cohc->busy = 1; 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); 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; cohc->completed = cohd_fin->desc.cookie;
/* release the lli allocation and remove the descriptor */ /* 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 */ /* return desc to free-list */
coh901318_desc_remove(cohd_fin); coh901318_desc_remove(cohd_fin);
@@ -666,23 +667,44 @@ static void dma_tasklet(unsigned long data)
/* called from interrupt context */ /* called from interrupt context */
static void dma_tc_handle(struct coh901318_chan *cohc) static void dma_tc_handle(struct coh901318_chan *cohc)
{ {
BUG_ON(!cohc->allocated && (list_empty(&cohc->active) || /*
list_empty(&cohc->queue))); * If the channel is not allocated, then we shouldn't have
* any TC interrupts on it.
if (!cohc->allocated) */
if (!cohc->allocated) {
dev_err(COHC_2_DEV(cohc), "spurious interrupt from "
"unallocated channel\n");
return; return;
}
spin_lock(&cohc->lock); 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++; 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) if (coh901318_queue_start(cohc) == NULL)
cohc->busy = 0; cohc->busy = 0;
BUG_ON(list_empty(&cohc->active));
spin_unlock(&cohc->lock); spin_unlock(&cohc->lock);
/*
* This tasklet will remove items from cohc->active
* and thus terminates them.
*/
if (cohc_chan_conf(cohc)->priority_high) if (cohc_chan_conf(cohc)->priority_high)
tasklet_hi_schedule(&cohc->tasklet); tasklet_hi_schedule(&cohc->tasklet);
else 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, coh901318_prep_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
size_t size, unsigned long flags) size_t size, unsigned long flags)
{ {
struct coh901318_lli *data; struct coh901318_lli *lli;
struct coh901318_desc *cohd; struct coh901318_desc *cohd;
unsigned long flg; unsigned long flg;
struct coh901318_chan *cohc = to_coh901318_chan(chan); 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) if ((lli_len << MAX_DMA_PACKET_SIZE_SHIFT) < size)
lli_len++; 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; goto err;
ret = coh901318_lli_fill_memcpy( 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, cohc_chan_param(cohc)->ctrl_lli_chained,
ctrl_last); ctrl_last);
if (ret) if (ret)
goto err; goto err;
COH_DBG(coh901318_list_print(cohc, data)); COH_DBG(coh901318_list_print(cohc, lli));
/* Pick a descriptor to handle this transfer */ /* Pick a descriptor to handle this transfer */
cohd = coh901318_desc_get(cohc); cohd = coh901318_desc_get(cohc);
cohd->data = data; cohd->lli = lli;
cohd->flags = flags; cohd->flags = flags;
cohd->desc.tx_submit = coh901318_tx_submit; 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) unsigned long flags)
{ {
struct coh901318_chan *cohc = to_coh901318_chan(chan); struct coh901318_chan *cohc = to_coh901318_chan(chan);
struct coh901318_lli *data; struct coh901318_lli *lli;
struct coh901318_desc *cohd; struct coh901318_desc *cohd;
const struct coh901318_params *params; const struct coh901318_params *params;
struct scatterlist *sg; 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); 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; goto err_dma_alloc;
/* initiate allocated data list */ /* initiate allocated lli list */
ret = coh901318_lli_fill_sg(&cohc->base->pool, data, sgl, sg_len, ret = coh901318_lli_fill_sg(&cohc->base->pool, lli, sgl, sg_len,
cohc_dev_addr(cohc), cohc_dev_addr(cohc),
ctrl_chained, ctrl_chained,
ctrl, ctrl,
@@ -1014,14 +1036,14 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
if (ret) if (ret)
goto err_lli_fill; 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 */ /* Pick a descriptor to handle this transfer */
cohd = coh901318_desc_get(cohc); cohd = coh901318_desc_get(cohc);
cohd->dir = direction; cohd->dir = direction;
cohd->flags = flags; cohd->flags = flags;
cohd->desc.tx_submit = coh901318_tx_submit; cohd->desc.tx_submit = coh901318_tx_submit;
cohd->data = data; cohd->lli = lli;
spin_unlock_irqrestore(&cohc->lock, flg); spin_unlock_irqrestore(&cohc->lock, flg);
@@ -1065,7 +1087,12 @@ coh901318_issue_pending(struct dma_chan *chan)
spin_lock_irqsave(&cohc->lock, flags); 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) if (!cohc->busy)
coh901318_queue_start(cohc); coh901318_queue_start(cohc);
@@ -1099,7 +1126,7 @@ coh901318_terminate_all(struct dma_chan *chan)
while ((cohd = coh901318_first_active_get(cohc))) { while ((cohd = coh901318_first_active_get(cohc))) {
/* release the lli allocation*/ /* 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 */ /* return desc to free-list */
coh901318_desc_remove(cohd); coh901318_desc_remove(cohd);
@@ -1108,7 +1135,7 @@ coh901318_terminate_all(struct dma_chan *chan)
while ((cohd = coh901318_first_queued(cohc))) { while ((cohd = coh901318_first_queued(cohc))) {
/* release the lli allocation*/ /* 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 */ /* return desc to free-list */
coh901318_desc_remove(cohd); coh901318_desc_remove(cohd);