Re: [PATCH v2 03/14] staging: iio: ad7746: Fix bound checkings
From: HernÃn Gonzalez
Date: Mon Apr 16 2018 - 10:47:33 EST
On Sun, Apr 15, 2018 at 12:05 PM, Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
> On Fri, 13 Apr 2018 13:36:40 -0300
> HernÃn Gonzalez <hernan@xxxxxxxxxxxxxxxxxxxx> wrote:
>
>> Also remove unnecessary parenthesis
> I am probably missing something. I'm not sure what you mean
> by fix bound checking? There are superfluous brackets, but
> I don't see any functional change to indicate there was anything
> wrong with the original checks.
>
Maybe I'm wrong but | is a bitwise operator while || is a logical one.
There are no functional changes as you said but, from K&R, "One must
distinguish the bitwise operators & and | from the logical operators
&& and II, which imply left-to-right evaluation of a truth value. For
example, if x is 1 and y is 2, then x & y is zero while x && y is one"
so it'd be slightly faster if the first condition is true, and it
would be the "correct" operator to use in this case, even though it
doesn't affect the result.
>>
>> Signed-off-by: HernÃn Gonzalez <hernan@xxxxxxxxxxxxxxxxxxxx>
>> ---
>> drivers/staging/iio/cdc/ad7746.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/staging/iio/cdc/ad7746.c b/drivers/staging/iio/cdc/ad7746.c
>> index 516aa93..d793785 100644
>> --- a/drivers/staging/iio/cdc/ad7746.c
>> +++ b/drivers/staging/iio/cdc/ad7746.c
>> @@ -458,7 +458,7 @@ static int ad7746_write_raw(struct iio_dev *indio_dev,
>> ret = 0;
>> break;
>> case IIO_CHAN_INFO_CALIBBIAS:
>> - if ((val < 0) | (val > 0xFFFF)) {
>> + if (val < 0 || val > 0xFFFF) {
>> ret = -EINVAL;
>> goto out;
>> }
>> @@ -470,7 +470,7 @@ static int ad7746_write_raw(struct iio_dev *indio_dev,
>> ret = 0;
>> break;
>> case IIO_CHAN_INFO_OFFSET:
>> - if ((val < 0) | (val > 43008000)) { /* 21pF */
>> + if (val < 0 || val > 43008000) { /* 21pF */
>> ret = -EINVAL;
>> goto out;
>> }
>