Re: [PATCH] scsi: remove useless variable assignment

[Gustavo A. R. Silva]

Hi James,

Quoting James Bottomley <jejb@xxxxxxxxxxxxxxxxxx>:

> On Wed, 2017-05-17 at 19:30 -0500, Gustavo A. R. Silva wrote:
> > Remove this assignment once the value stored in variable _k_ is
> > overwritten after a few lines.
> >
> > Addresses-Coverity-ID: 1226927
> > Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
> > ---
> >  drivers/scsi/qlogicfas408.c | 1 -
> >  1 file changed, 1 deletion(-)
> >
> > diff --git a/drivers/scsi/qlogicfas408.c
> > b/drivers/scsi/qlogicfas408.c
> > index c3a9151..269440a 100644
> > --- a/drivers/scsi/qlogicfas408.c
> > +++ b/drivers/scsi/qlogicfas408.c
> > @@ -329,7 +329,6 @@ static unsigned int ql_pcmd(struct scsi_cmnd
> > *cmd)
> >  		 */
> >  		if ((k = ql_wai(priv)))
> >  			return (k << 16);
> > -		k = inb(qbase + 5);	/* should be 0x10, bus
> > service */
>
> That doesn't look right to me.  inb() is a statement which has an
> effect on the I/O device regardless of whether the returned value is
> used or discarded.  In this case I think it's being used to clear
> pending interrupts, so removing it will likely cause a phase error.

You are right, I get it.

In this case I think a patch to ignore the return value could be applied:

index c3a9151..8f5339a 100644
--- a/drivers/scsi/qlogicfas408.c
+++ b/drivers/scsi/qlogicfas408.c
@@ -329,7 +329,7 @@ static unsigned int ql_pcmd(struct scsi_cmnd *cmd)
                 */
                if ((k = ql_wai(priv)))
                        return (k << 16);
-               k = inb(qbase + 5);     /* should be 0x10, bus service */
+               inb(qbase + 5); /* should be 0x10, bus service */
        }

What do you think?

Thank you for the clarification.
--
Gustavo A. R. Silva