[PATCH v2 5/5] staging: dgap: tty.c: removes smatch warning "unsigned '--un->un_open_count' is never less than zero"

[Lidza Louina]

On Thu, Sep 26, 2013 at 6:22 AM, Dan Carpenter <dan.carpenter at oracle.com> wrote:
> On Wed, Sep 25, 2013 at 07:08:54PM -0400, Lidza Louina wrote:
>> This patch removes this smatch warning:
>> unsigned '--un->un_open_count' is never less than zero
>>
>> The code decremented the un_open_count variable
>> and tested to see if it was less than zero. Because
>> un_open_count is unsigned and can't be below zero,
>> this test didn't work.
>>
>> Signed-off-by: Lidza Louina <lidza.louina at gmail.com>
>> ---
>>  drivers/staging/dgap/dgap_tty.c | 8 +++-----
>>  1 file changed, 3 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/staging/dgap/dgap_tty.c b/drivers/staging/dgap/dgap_tty.c
>> index 3e12ddb..c0258db 100644
>> --- a/drivers/staging/dgap/dgap_tty.c
>> +++ b/drivers/staging/dgap/dgap_tty.c
>> @@ -1446,13 +1446,11 @@ static void dgap_tty_close(struct tty_struct *tty, struct file *file)
>>               APR(("tty->count is 1, un open count is %d\n", un->un_open_count));
>>               un->un_open_count = 1;
>>       }
>> -
>> -     if (--un->un_open_count < 0) {
>> +     if (un->un_open_count == 0) {
>>               APR(("bad serial port open count of %d\n", un->un_open_count));
>> -             un->un_open_count = 0;
>> +             un->un_open_count = 1;
>>       }
>> -
>> -     ch->ch_open_count--;
>
> Wait?  Don't delete this line.  We need to decrement both.
>
>> +     un->un_open_count--;
>
> regards,
> dan carpenter
>
>

Ahh, I see. I'll resend this patch.