THe pcl816_ai_setup_dma() and pcl816_ai_setup_next_dma() functions are similar
other than the buffer switch and the inclusion of the "unread_samples" in
pcl818_ai_setup_next_dma() when calculating the dma size.
Merge these two functions by initializing the 'dma->cur_dma' in the callers
and passing '0' for the "unread_samples" when first starting the DMA.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/pcl816.c | 43 +++++++++------------------------
1 file changed, 11 insertions(+), 32 deletions(-)
diff --git a/drivers/staging/comedi/drivers/pcl816.c b/drivers/staging/comedi/drivers/pcl816.c
index 88c89df..da35edf 100644
--- a/drivers/staging/comedi/drivers/pcl816.c
+++ b/drivers/staging/comedi/drivers/pcl816.c
@@ -142,47 +142,22 @@ static void pcl816_start_pacer(struct comedi_device *dev, bool load_counters)
}
static void pcl816_ai_setup_dma(struct comedi_device *dev,
- struct comedi_subdevice *s)
-{
- struct pcl816_private *devpriv = dev->private;
- struct comedi_isadma *dma = devpriv->dma;
- struct comedi_isadma_desc *desc = &dma->desc[0];
- unsigned int nsamples;
-
- dma->cur_dma = 0;
-
- /*
- * Determine dma size based on the buffer maxsize and the number of
- * samples remaining in the command.
- */
- nsamples = comedi_bytes_to_samples(s, desc->maxsize);
- nsamples = comedi_nsamples_left(s, nsamples);
- desc->size = comedi_samples_to_bytes(s, nsamples);
- comedi_isadma_program(desc);
-}
-
-static void pcl816_ai_setup_next_dma(struct comedi_device *dev,
- struct comedi_subdevice *s,
- unsigned int unread_samples)
+ struct comedi_subdevice *s,
+ unsigned int unread_samples)
{
struct pcl816_private *devpriv = dev->private;
struct comedi_isadma *dma = devpriv->dma;
- struct comedi_isadma_desc *desc;
- unsigned int max_samples;
+ struct comedi_isadma_desc *desc = &dma->desc[dma->cur_dma];
+ unsigned int max_samples = comedi_bytes_to_samples(s, desc->maxsize);
unsigned int nsamples;
comedi_isadma_disable(dma->chan);
- dma->cur_dma = 1 - dma->cur_dma;
- desc = &dma->desc[dma->cur_dma];
-
/*
* Determine dma size based on the buffer maxsize plus the number of
* unread samples and the number of samples remaining in the command.
*/
- max_samples = comedi_bytes_to_samples(s, desc->maxsize);
- nsamples = max_samples + unread_samples;
- nsamples = comedi_nsamples_left(s, nsamples);
+ nsamples = comedi_nsamples_left(s, max_samples + unread_samples);
if (nsamples > unread_samples) {
nsamples -= unread_samples;
desc->size = comedi_samples_to_bytes(s, nsamples);
@@ -321,7 +296,9 @@ static irqreturn_t pcl816_interrupt(int irq, void *d)
bufptr = devpriv->ai_poll_ptr;
devpriv->ai_poll_ptr = 0;
- pcl816_ai_setup_next_dma(dev, s, nsamples);
+ /* restart dma with the next buffer */
+ dma->cur_dma = 1 - dma->cur_dma;
+ pcl816_ai_setup_dma(dev, s, nsamples);
transfer_from_dma_buf(dev, s, desc->virt_addr, bufptr, nsamples);
@@ -485,7 +462,9 @@ static int pcl816_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
devpriv->ai_poll_ptr = 0;
devpriv->ai_cmd_canceled = 0;
- pcl816_ai_setup_dma(dev, s);
+ /* setup and enable dma for the first buffer */
+ dma->cur_dma = 0;
+ pcl816_ai_setup_dma(dev, s, 0);
pcl816_start_pacer(dev, true);
--
2.0.3
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