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dmaengine: edma: Simplify and optimize the edma_execute path 

The code path in edma_execute() and edma_callback() can be simplified
and make it more optimal.
There is not need to call in to edma_execute() when the transfer
has been finished for example.
Also the handling of missed/first or next batch of paRAMs can
be done in a more optimal way.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
This commit is contained in:
Peter Ujfalusi 2015-10-14 14:42:45 +03:00 committed by Vinod Koul
parent d28c2b36d6
commit 8fa7ff4fc0
1 changed files with 29 additions and 47 deletions
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76
drivers/dma/edma.c
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@ -154,15 +154,11 @@ static void edma_execute(struct edma_chan *echan)
struct device *dev = echan->vchan.chan.device->dev;
int i, j, left, nslots;
/* If either we processed all psets or we're still not started */
if (!echan->edesc ||
echan->edesc->pset_nr == echan->edesc->processed) {
/* Get next vdesc */
if (!echan->edesc) {
/* Setup is needed for the first transfer */
vdesc = vchan_next_desc(&echan->vchan);
if (!vdesc) {
echan->edesc = NULL;
if (!vdesc)
return;
}
list_del(&vdesc->node);
echan->edesc = to_edma_desc(&vdesc->tx);
}
@ -220,7 +216,19 @@ static void edma_execute(struct edma_chan *echan)
echan->ecc->dummy_slot);
}
if (edesc->processed <= MAX_NR_SG) {
if (echan->missed) {
/*
* This happens due to setup times between intermediate
* transfers in long SG lists which have to be broken up into
* transfers of MAX_NR_SG
*/
dev_dbg(dev, "missed event on channel %d\n", echan->ch_num);
edma_clean_channel(echan->ch_num);
edma_stop(echan->ch_num);
edma_start(echan->ch_num);
edma_trigger_channel(echan->ch_num);
echan->missed = 0;
} else if (edesc->processed <= MAX_NR_SG) {
dev_dbg(dev, "first transfer starting on channel %d\n",
echan->ch_num);
edma_start(echan->ch_num);
@ -229,20 +237,6 @@ static void edma_execute(struct edma_chan *echan)
echan->ch_num, edesc->processed);
edma_resume(echan->ch_num);
}
/*
* This happens due to setup times between intermediate transfers
* in long SG lists which have to be broken up into transfers of
* MAX_NR_SG
*/
if (echan->missed) {
dev_dbg(dev, "missed event on channel %d\n", echan->ch_num);
edma_clean_channel(echan->ch_num);
edma_stop(echan->ch_num);
edma_start(echan->ch_num);
edma_trigger_channel(echan->ch_num);
echan->missed = 0;
}
}
static int edma_terminate_all(struct dma_chan *chan)
@ -259,20 +253,17 @@ static int edma_terminate_all(struct dma_chan *chan)
* echan->edesc is NULL and exit.)
*/
if (echan->edesc) {
int cyclic = echan->edesc->cyclic;
edma_stop(echan->ch_num);
/* Move the cyclic channel back to default queue */
if (echan->edesc->cyclic)
edma_assign_channel_eventq(echan->ch_num,
EVENTQ_DEFAULT);
/*
* free the running request descriptor
* since it is not in any of the vdesc lists
*/
edma_desc_free(&echan->edesc->vdesc);
echan->edesc = NULL;
edma_stop(echan->ch_num);
/* Move the cyclic channel back to default queue */
if (cyclic)
edma_assign_channel_eventq(echan->ch_num,
EVENTQ_DEFAULT);
}
vchan_get_all_descriptors(&echan->vchan, &head);
@ -725,41 +716,33 @@ static void edma_callback(unsigned ch_num, u16 ch_status, void *data)
edesc = echan->edesc;
/* Pause the channel for non-cyclic */
if (!edesc || (edesc && !edesc->cyclic))
edma_pause(echan->ch_num);
spin_lock(&echan->vchan.lock);
switch (ch_status) {
case EDMA_DMA_COMPLETE:
spin_lock(&echan->vchan.lock);
if (edesc) {
if (edesc->cyclic) {
vchan_cyclic_callback(&edesc->vdesc);
goto out;
} else if (edesc->processed == edesc->pset_nr) {
dev_dbg(dev, "Transfer complete, stopping channel %d\n", ch_num);
edesc->residue = 0;
edma_stop(echan->ch_num);
vchan_cookie_complete(&edesc->vdesc);
edma_execute(echan);
echan->edesc = NULL;
} else {
dev_dbg(dev, "Intermediate transfer complete on channel %d\n", ch_num);
edma_pause(echan->ch_num);
/* Update statistics for tx_status */
edesc->residue -= edesc->sg_len;
edesc->residue_stat = edesc->residue;
edesc->processed_stat = edesc->processed;
edma_execute(echan);
}
edma_execute(echan);
}
spin_unlock(&echan->vchan.lock);
break;
case EDMA_DMA_CC_ERROR:
spin_lock(&echan->vchan.lock);
edma_read_slot(EDMA_CHAN_SLOT(echan->slot[0]), &p);
/*
@ -788,13 +771,12 @@ static void edma_callback(unsigned ch_num, u16 ch_status, void *data)
edma_start(echan->ch_num);
edma_trigger_channel(echan->ch_num);
}
spin_unlock(&echan->vchan.lock);
break;
default:
break;
}
out:
spin_unlock(&echan->vchan.lock);
}
/* Alloc channel resources */