Add a static inline function to "ni_labpc_isadma.h" to test if a DMA
channel has been set-up, in which case `devpriv->dma_chan` will be
non-zero (where `devpriv` point to the private data for the comedi
device). If the "ni_labpc_isadma" module is not being built, don't
bother checking `devpriv->dma_chan`; just return `false` as this may
help the compiler to optimize out some unreachable code.
Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx>
---
drivers/staging/comedi/drivers/ni_labpc_isadma.h | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/staging/comedi/drivers/ni_labpc_isadma.h b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
index 144f4ba..3b022ea 100644
--- a/drivers/staging/comedi/drivers/ni_labpc_isadma.h
+++ b/drivers/staging/comedi/drivers/ni_labpc_isadma.h
@@ -9,11 +9,23 @@
#if NI_LABPC_HAVE_ISA_DMA
+static inline bool labpc_have_dma_chan(struct comedi_device *dev)
+{
+ struct labpc_private *devpriv = dev->private;
+
+ return (bool)devpriv->dma_chan;
+}
+
int labpc_init_dma_chan(struct comedi_device *dev, unsigned int dma_chan);
void labpc_free_dma_chan(struct comedi_device *dev);
#else
+static inline bool labpc_have_dma_chan(struct comedi_device *dev)
+{
+ return false;
+}
+
static inline int labpc_init_dma_chan(struct comedi_device *dev,
unsigned int dma_chan)
{
--
1.8.2.1
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