[PATCH 2/2] ARM: mx5/mx53_evk: Remove unneeded gpio_set_value call

[Julia Lawall]

On Mon, 21 Mar 2011, Grant Likely wrote:

> 2011/3/15 Julia Lawall <julia at diku.dk>:
> > On Tue, 15 Mar 2011, Uwe Kleine-König wrote:
> >
> >> On Tue, Mar 15, 2011 at 10:41:37AM +0100, Julia Lawall wrote:
> >> > I tried the following
> >> >
> >> > @@
> >> > expression E1,E2;
> >> > @@
> >> >
> >> >       gpio_direction_output(E1,E2);
> >> >       ...
> >> > -     gpio_set_value(E1,E2);
> >> >
> >> > and found occurrences in 15 files.  In some cases there seems to be some
> >> > delay before the call to gpio_set_value.  Does that have any impacton
> >> > whether it is needed?
> >> gpio_direction_output(E1,E2) implies gpio_set_value(E1,E2), so unless
> >> there is a gpio_set_value(E1,!E2) before gpio_set_value(E1,E2) is a
> >> noop.
> >>
> >> I still don't know how to work with coccinelle, so if you point me to a
> >> concrete location I can be more specific.
> >
> > OK.  I have changed the semantic patch to the following:
> >
> > @@
> > expression E1,E2,E3;
> > @@
> >
> >      gpio_direction_output(E1,E2);
> >      ... when != gpio_set_value(E1,E3)
> > -     gpio_set_value(E1,E2);
> >
> > Now it doesn't do all the cases where there is an earlier set ofr some
> > other value.  The patch I obtain is below.  This only concerns 5 files.
> > I haven't checked the result at all.
> >
> > julia
> 
> Hi Julia,
> 
> Similar to my other reply, even though this patch is much smaller, I'm
> not particularly excited about changing all the drivers wholesale
> unless someone with hardware can give it a test.

I wasn't proposing either as an actual patch.  Only as a way to see what 
the actual code looks like and what issues should be taken into account.

thanks,
julia