Re: [patch] TTY: synclink, small cleanup in dtr_rts()

Dan Carpenter
2013-01-27T20:21:37Z

On Sun, Jan 27, 2013 at 12:04:38PM -0800, Joe Perches wrote:
> On Sun, 2013-01-27 at 22:40 +0300, Dan Carpenter wrote:
> > There is a kind of precedence problem here, but it doesn't affect how
> > the code works because ->serial_signals is unsigned char. We want to
> > clear two flags here.
> >
> > #define SerialSignal_RTS 0x20 /* Request to Send */
> > #define SerialSignal_DTR 0x80 /* Data Terminal Ready */
> >
> > Without the parenthesis then it does:
> >
> > info->serial_signals &= 0x5f;
> >
> > With the parenthesis it does:
> >
> > info->serial_signals &= 0xffffff5f;
> >
> > info->serial_signals is an unsigned char so the two statements are
> > equivalent, but it's cleaner to add the parenthesis. In other dtr_rts()
> > functions the parenthesis are there so this makes it more consistent.
>
>
> Wouldn't it be clearer still to use | instead of +
>

Yeah. I think it would be, but adding bitflags together instead of
doing bitwise ORs is very common as well.

I would Ack the patch you sent though.

regards,
dan carpenter