An IRQ and at least one DMA channel are required to use DMA with this driver.
Move the check to the caller to reduce the indent level of this function.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/das1800.c | 129 ++++++++++++++++---------------
1 file changed, 65 insertions(+), 64 deletions(-)
diff --git a/drivers/staging/comedi/drivers/das1800.c b/drivers/staging/comedi/drivers/das1800.c
index be825d2..c415b57 100644
--- a/drivers/staging/comedi/drivers/das1800.c
+++ b/drivers/staging/comedi/drivers/das1800.c
@@ -1240,72 +1240,70 @@ static int das1800_init_dma(struct comedi_device *dev, unsigned int dma0,
struct das1800_private *devpriv = dev->private;
unsigned long flags;
- /* need an irq to do dma */
- if (dev->irq && dma0) {
- /* encode dma0 and dma1 into 2 digit hexadecimal for switch */
- switch ((dma0 & 0x7) | (dma1 << 4)) {
- case 0x5: /* dma0 == 5 */
- devpriv->dma_bits |= DMA_CH5;
- break;
- case 0x6: /* dma0 == 6 */
- devpriv->dma_bits |= DMA_CH6;
- break;
- case 0x7: /* dma0 == 7 */
- devpriv->dma_bits |= DMA_CH7;
- break;
- case 0x65: /* dma0 == 5, dma1 == 6 */
- devpriv->dma_bits |= DMA_CH5_CH6;
- break;
- case 0x76: /* dma0 == 6, dma1 == 7 */
- devpriv->dma_bits |= DMA_CH6_CH7;
- break;
- case 0x57: /* dma0 == 7, dma1 == 5 */
- devpriv->dma_bits |= DMA_CH7_CH5;
- break;
- default:
- dev_err(dev->class_dev,
- "only supports dma channels 5 through 7\n");
- dev_err(dev->class_dev,
- "Dual dma only allows the following combinations:\n");
- dev_err(dev->class_dev,
- "dma 5,6 / 6,7 / or 7,5\n");
- return -EINVAL;
- }
- if (request_dma(dma0, dev->driver->driver_name)) {
+ /* encode dma0 and dma1 into 2 digit hexadecimal for switch */
+ switch ((dma0 & 0x7) | (dma1 << 4)) {
+ case 0x5: /* dma0 == 5 */
+ devpriv->dma_bits |= DMA_CH5;
+ break;
+ case 0x6: /* dma0 == 6 */
+ devpriv->dma_bits |= DMA_CH6;
+ break;
+ case 0x7: /* dma0 == 7 */
+ devpriv->dma_bits |= DMA_CH7;
+ break;
+ case 0x65: /* dma0 == 5, dma1 == 6 */
+ devpriv->dma_bits |= DMA_CH5_CH6;
+ break;
+ case 0x76: /* dma0 == 6, dma1 == 7 */
+ devpriv->dma_bits |= DMA_CH6_CH7;
+ break;
+ case 0x57: /* dma0 == 7, dma1 == 5 */
+ devpriv->dma_bits |= DMA_CH7_CH5;
+ break;
+ default:
+ dev_err(dev->class_dev,
+ "only supports dma channels 5 through 7\n");
+ dev_err(dev->class_dev,
+ "Dual dma only allows the following combinations:\n");
+ dev_err(dev->class_dev,
+ "dma 5,6 / 6,7 / or 7,5\n");
+ return -EINVAL;
+ }
+ if (request_dma(dma0, dev->driver->driver_name)) {
+ dev_err(dev->class_dev,
+ "failed to allocate dma channel %i\n", dma0);
+ return -EINVAL;
+ }
+ devpriv->dma0 = dma0;
+ devpriv->dma_current = dma0;
+ if (dma1) {
+ if (request_dma(dma1, dev->driver->driver_name)) {
dev_err(dev->class_dev,
- "failed to allocate dma channel %i\n", dma0);
+ "failed to allocate dma channel %i\n",
+ dma1);
return -EINVAL;
}
- devpriv->dma0 = dma0;
- devpriv->dma_current = dma0;
- if (dma1) {
- if (request_dma(dma1, dev->driver->driver_name)) {
- dev_err(dev->class_dev,
- "failed to allocate dma channel %i\n",
- dma1);
- return -EINVAL;
- }
- devpriv->dma1 = dma1;
- }
- devpriv->ai_buf0 = kmalloc(DMA_BUF_SIZE, GFP_KERNEL | GFP_DMA);
- if (devpriv->ai_buf0 == NULL)
+ devpriv->dma1 = dma1;
+ }
+ devpriv->ai_buf0 = kmalloc(DMA_BUF_SIZE, GFP_KERNEL | GFP_DMA);
+ if (devpriv->ai_buf0 == NULL)
+ return -ENOMEM;
+ devpriv->dma_current_buf = devpriv->ai_buf0;
+ if (dma1) {
+ devpriv->ai_buf1 =
+ kmalloc(DMA_BUF_SIZE, GFP_KERNEL | GFP_DMA);
+ if (devpriv->ai_buf1 == NULL)
return -ENOMEM;
- devpriv->dma_current_buf = devpriv->ai_buf0;
- if (dma1) {
- devpriv->ai_buf1 =
- kmalloc(DMA_BUF_SIZE, GFP_KERNEL | GFP_DMA);
- if (devpriv->ai_buf1 == NULL)
- return -ENOMEM;
- }
- flags = claim_dma_lock();
- disable_dma(devpriv->dma0);
- set_dma_mode(devpriv->dma0, DMA_MODE_READ);
- if (dma1) {
- disable_dma(devpriv->dma1);
- set_dma_mode(devpriv->dma1, DMA_MODE_READ);
- }
- release_dma_lock(flags);
}
+ flags = claim_dma_lock();
+ disable_dma(devpriv->dma0);
+ set_dma_mode(devpriv->dma0, DMA_MODE_READ);
+ if (dma1) {
+ disable_dma(devpriv->dma1);
+ set_dma_mode(devpriv->dma1, DMA_MODE_READ);
+ }
+ release_dma_lock(flags);
+
return 0;
}
@@ -1437,9 +1435,12 @@ static int das1800_attach(struct comedi_device *dev,
}
}
- ret = das1800_init_dma(dev, dma0, dma1);
- if (ret < 0)
- return ret;
+ /* an irq and one dma channel is required to use dma */
+ if (dev->irq & dma0) {
+ ret = das1800_init_dma(dev, dma0, dma1);
+ if (ret < 0)
+ return ret;
+ }
if (devpriv->ai_buf0 == NULL) {
devpriv->ai_buf0 =
--
2.0.3
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