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/pcl812.c | 63 ++++++++++++++-------------------
1 file changed, 27 insertions(+), 36 deletions(-)
diff --git a/drivers/staging/comedi/drivers/pcl812.c b/drivers/staging/comedi/drivers/pcl812.c
index b2a5a43..9ff15b0 100644
--- a/drivers/staging/comedi/drivers/pcl812.c
+++ b/drivers/staging/comedi/drivers/pcl812.c
@@ -522,10 +522,10 @@ struct pcl812_private {
unsigned int ai_act_scan; /* how many scans we finished */
unsigned int ai_chanlist[MAX_CHANLIST_LEN]; /* our copy of channel/range list */
unsigned int ai_data_len; /* len of data buffer */
+ unsigned int dmapages;
+ unsigned int hwdmasize;
unsigned long dmabuf[2]; /* PTR to DMA buf */
- unsigned int dmapages[2]; /* how many pages we have allocated */
unsigned int hwdmaptr[2]; /* HW PTR to DMA buf */
- unsigned int hwdmasize[2]; /* DMA buf size in bytes */
unsigned int dmabytestomove[2]; /* how many bytes DMA transfer */
int next_dma_buf; /* which buffer is next to use */
unsigned int dma_runs_to_end; /* how many times we must switch DMA buffers */
@@ -814,14 +814,14 @@ static int pcl812_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
cmd->chanlist_len * sizeof(short);
devpriv->dma_runs_to_end = 1;
} else {
- devpriv->dmabytestomove[0] = devpriv->hwdmasize[0];
- devpriv->dmabytestomove[1] = devpriv->hwdmasize[1];
- if (devpriv->ai_data_len < devpriv->hwdmasize[0])
+ devpriv->dmabytestomove[0] = devpriv->hwdmasize;
+ devpriv->dmabytestomove[1] = devpriv->hwdmasize;
+ if (devpriv->ai_data_len < devpriv->hwdmasize) {
devpriv->dmabytestomove[0] =
devpriv->ai_data_len;
- if (devpriv->ai_data_len < devpriv->hwdmasize[1])
devpriv->dmabytestomove[1] =
devpriv->ai_data_len;
+ }
if (devpriv->ai_neverending) {
devpriv->dma_runs_to_end = 1;
} else {
@@ -842,12 +842,12 @@ static int pcl812_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
devpriv->dma_runs_to_end--;
}
}
- if (devpriv->dmabytestomove[0] > devpriv->hwdmasize[0]) {
- devpriv->dmabytestomove[0] = devpriv->hwdmasize[0];
+ if (devpriv->dmabytestomove[0] > devpriv->hwdmasize) {
+ devpriv->dmabytestomove[0] = devpriv->hwdmasize;
devpriv->ai_eos = 0;
}
- if (devpriv->dmabytestomove[1] > devpriv->hwdmasize[1]) {
- devpriv->dmabytestomove[1] = devpriv->hwdmasize[1];
+ if (devpriv->dmabytestomove[1] > devpriv->hwdmasize) {
+ devpriv->dmabytestomove[1] = devpriv->hwdmasize;
devpriv->ai_eos = 0;
}
devpriv->next_dma_buf = 0;
@@ -1303,10 +1303,11 @@ static int pcl812_attach(struct comedi_device *dev, struct comedi_devconfig *it)
{
const struct pcl812_board *board = comedi_board(dev);
struct pcl812_private *devpriv;
- int ret, subdev;
- unsigned long pages;
struct comedi_subdevice *s;
int n_subdevices;
+ int subdev;
+ int ret;
+ int i;
ret = comedi_request_region(dev, it->options[0], 0x10);
if (ret)
@@ -1335,29 +1336,19 @@ static int pcl812_attach(struct comedi_device *dev, struct comedi_devconfig *it)
}
devpriv->dma = it->options[2];
- pages = 1; /* we want 8KB */
- devpriv->dmabuf[0] = __get_dma_pages(GFP_KERNEL, pages);
- 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] = PAGE_SIZE * (1 << pages);
- 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;
+ devpriv->dmapages = 1; /* we want 8KB */
+ devpriv->hwdmasize = (1 << devpriv->dmapages) * PAGE_SIZE;
+
+ for (i = 0; i < 2; i++) {
+ unsigned long dmabuf;
+
+ 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] = PAGE_SIZE * (1 << pages);
}
/* differential analog inputs? */
@@ -1500,9 +1491,9 @@ static void pcl812_detach(struct comedi_device *dev)
if (devpriv) {
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);
if (devpriv->dma)
free_dma(devpriv->dma);
}
--
1.8.5.2
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