Re: [PATCH] Staging: comedi: clean up conditional statement in addi_apci_3xxx.c

From: Ian Abbott
Date: Thu Feb 13 2014 - 05:09:10 EST


On 2014-02-13 03:29, Chase Southwood wrote:
In this if-else conditional statement, if (chan < 16), but
(data[0] == INSN_CONFIG_DIO_QUERY), the function does not return early,
but the else-branch does not get executed either. As a result, mask
would be used uninitialized in the next line. What we want here is if
(chan < 16) and (data[0] != INSN_CONFIG_DIO_QUERY), return an error, but
in every other case, initialize mask and then proceed. Found by a static
checker.

Signed-off-by: Chase Southwood <chase.southwood@xxxxxxxxx>
---
drivers/staging/comedi/drivers/addi_apci_3xxx.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/comedi/drivers/addi_apci_3xxx.c b/drivers/staging/comedi/drivers/addi_apci_3xxx.c
index ceadf8e..04c5153 100644
--- a/drivers/staging/comedi/drivers/addi_apci_3xxx.c
+++ b/drivers/staging/comedi/drivers/addi_apci_3xxx.c
@@ -688,13 +688,11 @@ static int apci3xxx_dio_insn_config(struct comedi_device *dev,
* Port 1 (channels 8-15) are always outputs
* Port 2 (channels 16-23) are programmable i/o
*/
- if (chan < 16) {
- if (data[0] != INSN_CONFIG_DIO_QUERY)
- return -EINVAL;
- } else {
- /* changing any channel in port 2 changes the entire port */
- mask = 0xff0000;
- }
+ if ((chan < 16) && (data[0] != INSN_CONFIG_DIO_QUERY))
+ return -EINVAL;
+
+ /* changing any channel in port 2 changes the entire port */
+ mask = 0xff0000;

ret = comedi_dio_insn_config(dev, s, insn, data, mask);
if (ret)

Seems correct.

Acked-by: Ian Abbott <abbotti@xxxxxxxxx>


--
-=( Ian Abbott @ MEV Ltd. E-mail: <abbotti@xxxxxxxxx> )=-
-=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=-
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