This driver uses 2 buffers for DMA. Refactor the buffer allocation to
use a for loop to remove code duplication. Remove the dev_err() messages
when __get_dma_pages() fails and change the errno returned from -EBUSY
to -ENOMEM.
Both buffers are the same size so replace the 'dmapages' and 'hwdmasize'
arrays in the private data with variables to save a bit of space.
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 | 68 ++++++++++++---------------------
1 file changed, 25 insertions(+), 43 deletions(-)
diff --git a/drivers/staging/comedi/drivers/pcl816.c b/drivers/staging/comedi/drivers/pcl816.c
index 3074da3..f62f631 100644
--- a/drivers/staging/comedi/drivers/pcl816.c
+++ b/drivers/staging/comedi/drivers/pcl816.c
@@ -109,12 +109,11 @@ static const struct pcl816_board boardtypes[] = {
};
struct pcl816_private {
-
unsigned int dma; /* used DMA, 0=don't use DMA */
+ unsigned int dmapages;
+ unsigned int hwdmasize;
unsigned long dmabuf[2]; /* pointers to begin of DMA buffers */
- unsigned int dmapages[2]; /* len of DMA buffers in PAGE_SIZEs */
unsigned int hwdmaptr[2]; /* hardware address of DMA buffers */
- unsigned int hwdmasize[2]; /* len of DMA buffers in Bytes */
unsigned int dmasamplsize; /* size in samples hwdmasize[0]/2 */
int next_dma_buf; /* which DMA buffer will be used next round */
long dma_runs_to_end; /* how many we must permorm DMA transfer to end of record */
@@ -327,13 +326,10 @@ static irqreturn_t interrupt_pcl816_ai_mode13_dma(int irq, void *d)
/* clear_dma_ff (devpriv->dma); */
set_dma_addr(devpriv->dma,
devpriv->hwdmaptr[devpriv->next_dma_buf]);
- if (devpriv->dma_runs_to_end) {
- set_dma_count(devpriv->dma,
- devpriv->hwdmasize[devpriv->
- next_dma_buf]);
- } else {
+ if (devpriv->dma_runs_to_end)
+ set_dma_count(devpriv->dma, devpriv->hwdmasize);
+ else
set_dma_count(devpriv->dma, devpriv->last_dma_run);
- }
release_dma_lock(dma_flags);
enable_dma(devpriv->dma);
}
@@ -343,7 +339,7 @@ static irqreturn_t interrupt_pcl816_ai_mode13_dma(int irq, void *d)
ptr = (unsigned short *)devpriv->dmabuf[this_dma_buf];
- len = (devpriv->hwdmasize[0] >> 1) - devpriv->ai_poll_ptr;
+ len = (devpriv->hwdmasize >> 1) - devpriv->ai_poll_ptr;
bufptr = devpriv->ai_poll_ptr;
devpriv->ai_poll_ptr = 0;
@@ -516,7 +512,7 @@ static int pcl816_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
devpriv->ai_neverending = 1;
if (devpriv->dma) {
- bytes = devpriv->hwdmasize[0];
+ bytes = devpriv->hwdmasize;
if (!devpriv->ai_neverending) {
/* how many */
bytes = s->async->cmd.chanlist_len *
@@ -524,14 +520,13 @@ static int pcl816_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
sizeof(short);
/* how many DMA pages we must fill */
- devpriv->dma_runs_to_end = bytes /
- devpriv->hwdmasize[0];
+ devpriv->dma_runs_to_end = bytes / devpriv->hwdmasize;
/* on last dma transfer must be moved */
- devpriv->last_dma_run = bytes % devpriv->hwdmasize[0];
+ devpriv->last_dma_run = bytes % devpriv->hwdmasize;
devpriv->dma_runs_to_end--;
if (devpriv->dma_runs_to_end >= 0)
- bytes = devpriv->hwdmasize[0];
+ bytes = devpriv->hwdmasize;
} else
devpriv->dma_runs_to_end = -1;
@@ -596,7 +591,7 @@ static int pcl816_ai_poll(struct comedi_device *dev, struct comedi_subdevice *s)
}
/* where is now DMA in buffer */
- top1 = devpriv->hwdmasize[0] - top1;
+ top1 = devpriv->hwdmasize - top1;
top1 >>= 1; /* sample position */
top2 = top1 - devpriv->ai_poll_ptr;
if (top2 < 1) { /* no new samples */
@@ -828,10 +823,9 @@ static int pcl816_attach(struct comedi_device *dev, struct comedi_devconfig *it)
{
const struct pcl816_board *board = comedi_board(dev);
struct pcl816_private *devpriv;
- int ret;
- unsigned long pages;
- /* int i; */
struct comedi_subdevice *s;
+ int ret;
+ int i;
ret = comedi_request_region(dev, it->options[0], 0x10);
if (ret)
@@ -868,31 +862,19 @@ static int pcl816_attach(struct comedi_device *dev, struct comedi_devconfig *it)
}
devpriv->dma = it->options[2];
- pages = 2; /* we need 16KB */
- devpriv->dmabuf[0] = __get_dma_pages(GFP_KERNEL, pages);
+ devpriv->dmapages = 2; /* we need 16KB */
+ devpriv->hwdmasize = (1 << devpriv->dmapages) * PAGE_SIZE;
- if (!devpriv->dmabuf[0]) {
- dev_err(dev->class_dev,
- "unable to allocate DMA buffer, FAIL!\n");
- /*
- * maybe experiment with try_to_free_pages()
- * will help ....
- */
- return -EBUSY; /* no buffer :-( */
- }
- devpriv->dmapages[0] = pages;
- devpriv->hwdmaptr[0] = virt_to_bus((void *)devpriv->dmabuf[0]);
- devpriv->hwdmasize[0] = (1 << pages) * PAGE_SIZE;
+ for (i = 0; i < 2; i++) {
+ unsigned long dmabuf;
- devpriv->dmabuf[1] = __get_dma_pages(GFP_KERNEL, pages);
- if (!devpriv->dmabuf[1]) {
- dev_err(dev->class_dev,
- "unable to allocate DMA buffer, FAIL!\n");
- return -EBUSY;
+ dmabuf = __get_dma_pages(GFP_KERNEL, devpriv->dmapages);
+ if (!dmabuf)
+ return -ENOMEM;
+
+ devpriv->dmabuf[i] = dmabuf;
+ devpriv->hwdmaptr[i] = virt_to_bus((void *)dmabuf);
}
- devpriv->dmapages[1] = pages;
- devpriv->hwdmaptr[1] = virt_to_bus((void *)devpriv->dmabuf[1]);
- devpriv->hwdmasize[1] = (1 << pages) * PAGE_SIZE;
}
ret = comedi_alloc_subdevices(dev, 1);
@@ -954,9 +936,9 @@ static void pcl816_detach(struct comedi_device *dev)
if (devpriv->dma)
free_dma(devpriv->dma);
if (devpriv->dmabuf[0])
- free_pages(devpriv->dmabuf[0], devpriv->dmapages[0]);
+ free_pages(devpriv->dmabuf[0], devpriv->dmapages);
if (devpriv->dmabuf[1])
- free_pages(devpriv->dmabuf[1], devpriv->dmapages[1]);
+ free_pages(devpriv->dmabuf[1], devpriv->dmapages);
}
comedi_legacy_detach(dev);
}
--
1.8.5.2
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