Re: [PATCH][next] tty: serial: jsm: remove redundant assignments of several variables

From: Colin Ian King
Date: Thu Apr 22 2021 - 09:01:40 EST


On 22/04/2021 13:56, Johan Hovold wrote:
> On Thu, Apr 22, 2021 at 01:53:03PM +0100, Colin Ian King wrote:
>> On 22/04/2021 13:52, Johan Hovold wrote:
>>> On Thu, Apr 22, 2021 at 01:11:15PM +0100, Colin King wrote:
>>>> From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>>>>
>>>> Several variables are being assigned with values that are never
>>>> read and being updated later with a new value. The initializations
>>>> are redundant and can be removed.
>>>>
>>>> Addresses-Coverity: ("Unused value")
>>>> Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
>>>> ---
>>>> drivers/tty/serial/jsm/jsm_cls.c | 6 ++----
>>>> 1 file changed, 2 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/drivers/tty/serial/jsm/jsm_cls.c b/drivers/tty/serial/jsm/jsm_cls.c
>>>> index b507a2cec926..b58ea4344aaf 100644
>>>> --- a/drivers/tty/serial/jsm/jsm_cls.c
>>>> +++ b/drivers/tty/serial/jsm/jsm_cls.c
>>>> @@ -349,8 +349,8 @@ static void cls_assert_modem_signals(struct jsm_channel *ch)
>>>>
>>>> static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch)
>>>> {
>>>> - int qleft = 0;
>>>> - u8 linestatus = 0;
>>>> + int qleft;
>>>> + u8 linestatus;
>>>> u8 error_mask = 0;
>>>> u16 head;
>>>> u16 tail;
>>>> @@ -365,8 +365,6 @@ static void cls_copy_data_from_uart_to_queue(struct jsm_channel *ch)
>>>> head = ch->ch_r_head & RQUEUEMASK;
>>>> tail = ch->ch_r_tail & RQUEUEMASK;
>>>>
>>>> - /* Get our cached LSR */
>>>> - linestatus = ch->ch_cached_lsr;
>>>> ch->ch_cached_lsr = 0;
>>>
>>> Why leave this assignment in? Looks like this was all copy-pasta, but
>>> this assignment makes even less sense now that you remove the comment
>>> and load.
>>
>> Which assignment are you referring to?
>
> The one just above my comment:
>
> ch->ch_cached_lsr = 0;

that cached value is being used in jsm_neo.c, so removing the zero'ing
may cause some issues.

>
> Johan
>