[PATCH 6/8] drivers/staging/comedi/drivers: Fix unsigned return type

From: Julia Lawall
Date: Sun Sep 05 2010 - 14:59:48 EST


In each case, the function has an unsigned return type, but returns a
negative constant to indicate an error condition. For move_block_from_dma,
there is only one call and the return value is dropped, so it need not be
unsigned. For labpc_eeprom_write, there is only one call and the result is
stored in a signed variable, so again the unsigned return type is not
necessary.

A sematic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@exists@
identifier f;
constant C;
@@

unsigned f(...)
{ <+...
* return -C;
...+> }
// </smpl>

Signed-off-by: Julia Lawall <julia@xxxxxxx>

---
drivers/staging/comedi/drivers/adl_pci9118.c | 2 +-
drivers/staging/comedi/drivers/ni_labpc.c | 6 +++---
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/comedi/drivers/adl_pci9118.c b/drivers/staging/comedi/drivers/adl_pci9118.c
index a2bd4e6..cb2843d 100644
--- a/drivers/staging/comedi/drivers/adl_pci9118.c
+++ b/drivers/staging/comedi/drivers/adl_pci9118.c
@@ -634,7 +634,7 @@ static unsigned int defragment_dma_buffer(struct comedi_device *dev,
/*
==============================================================================
*/
-static unsigned int move_block_from_dma(struct comedi_device *dev,
+static int move_block_from_dma(struct comedi_device *dev,
struct comedi_subdevice *s,
short *dma_buffer,
unsigned int num_samples)
diff --git a/drivers/staging/comedi/drivers/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index 3acf7e6..19f79e8 100644
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -250,7 +250,7 @@ static unsigned int labpc_serial_in(struct comedi_device *dev);
static unsigned int labpc_eeprom_read(struct comedi_device *dev,
unsigned int address);
static unsigned int labpc_eeprom_read_status(struct comedi_device *dev);
-static unsigned int labpc_eeprom_write(struct comedi_device *dev,
+static int labpc_eeprom_write(struct comedi_device *dev,
unsigned int address,
unsigned int value);
static void write_caldac(struct comedi_device *dev, unsigned int channel,
@@ -1986,8 +1986,8 @@ static unsigned int labpc_eeprom_read(struct comedi_device *dev,
return value;
}

-static unsigned int labpc_eeprom_write(struct comedi_device *dev,
- unsigned int address, unsigned int value)
+static int labpc_eeprom_write(struct comedi_device *dev,
+ unsigned int address, unsigned int value)
{
const int write_enable_instruction = 0x6;
const int write_instruction = 0x2;

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