Re: [PATCH] tty: max3100: remove unused variable rts and remove unused assignment

Colin Ian King
2017-11-02T14:22:14Z

On 02/11/17 14:21, Colin Ian King wrote:
> On 02/11/17 14:14, walter harms wrote:
>>
>>
>> Am 02.11.2017 15:01, schrieb Colin King:
>>> From: Colin Ian King <colin.king@canonical.com>
>>>
>>> Variable rts is being assigned but it is never read, hence it can be
>>> removed. The assignment to param_new to zero is redundant as it is
>>> being updates a few statements later, so remove this redundant
>>> assignment. Cleans up two clang warnings:
>>>
>>> drivers/tty/serial/max3100.c:277:3: warning: Value stored to 'rts'
>>> is never read
>>> drivers/tty/serial/max3100.c:439:2: warning: Value stored to 'param_new'
>>> is never read
>>>
>>> Signed-off-by: Colin Ian King <colin.king@canonical.com>
>>> ---
>>> drivers/tty/serial/max3100.c | 4 +---
>>> 1 file changed, 1 insertion(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/tty/serial/max3100.c b/drivers/tty/serial/max3100.c
>>> index b6b3453e8c1f..f691f3cdb5b1 100644
>>> --- a/drivers/tty/serial/max3100.c
>>> +++ b/drivers/tty/serial/max3100.c
>>> @@ -263,7 +263,7 @@ static void max3100_work(struct work_struct *w)
>>> struct max3100_port *s = container_of(w, struct max3100_port, work);
>>> int rxchars;
>>> u16 tx, rx;
>>> - int conf, cconf, rts, crts;
>>> + int conf, cconf, crts;
>>> struct circ_buf *xmit = &s->port.state->xmit;
>>>
>>> dev_dbg(&s->spi->dev, "%s\n", __func__);
>>> @@ -274,7 +274,6 @@ static void max3100_work(struct work_struct *w)
>>> conf = s->conf;
>>> cconf = s->conf_commit;
>>> s->conf_commit = 0;
>>> - rts = s->rts;
>>> crts = s->rts_commit;
>>> s->rts_commit = 0;
>>> spin_unlock(&s->conf_lock);
>>> @@ -436,7 +435,6 @@ max3100_set_termios(struct uart_port *port, struct ktermios *termios,
>>> dev_dbg(&s->spi->dev, "%s\n", __func__);
>>>
>>> cflag = termios->c_cflag;
>>> - param_new = 0;
>>> param_mask = 0;
>>>
>>> baud = tty_termios_baud_rate(termios);
>>
>> are you sure ?
>
> Yep. So are my compilers
>
>>
>> based on this code:
>> https://lxr.missinglinkelectronics.com/linux/drivers/tty/serial/max3100.c
>
> 438 cflag = termios->c_cflag;
> 439 param_new = 0;
> 440 param_mask = 0;
> 441
> 442 baud = tty_termios_baud_rate(termios);
> 443 param_new = s->conf & MAX3100_BAUD;
>
> param_new is being updated again on line 440, so line 439 is redundant.
I mean "again on line 443"

>
>>
>> the default case will not set param_new
>>
>> re,
>> wh
>>
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>