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

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Message-ID: <YIFydeoE/WRfPcvA@hovoldconsulting.com>
Date:   Thu, 22 Apr 2021 14:56:21 +0200
From:   Johan Hovold <johan@...nel.org>
To:     Colin Ian King <colin.king@...onical.com>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Jiri Slaby <jirislaby@...nel.org>,
        Lee Jones <lee.jones@...aro.org>, linux-serial@...r.kernel.org,
        kernel-janitors@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH][next] tty: serial: jsm: remove redundant assignments of
 several variables

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@...onical.com>
> >>
> >> 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@...onical.com>
> >> ---
> >>  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;

Johan