Re: [PATCH] coccinelle: api: detect unnecessary le16_to_cpu
From: Sebastian Reichel
Date: Mon Jul 03 2017 - 14:20:49 EST
On Mon, Jul 03, 2017 at 08:33:53PM +0300, Andy Shevchenko wrote:
> On Mon, Jul 3, 2017 at 8:14 PM, Sebastian Reichel
> <sebastian.reichel@xxxxxxxxxxxxxxx> wrote:
> > On Mon, Jul 03, 2017 at 07:37:59PM +0300, Andy Shevchenko wrote:
> >> On Mon, Jul 3, 2017 at 4:36 PM, Sebastian Reichel
> >> <sebastian.reichel@xxxxxxxxxxxxxxx> wrote:
> >> > On Sat, Jul 01, 2017 at 09:28:10PM +0200, Julia Lawall wrote:
> >> > * drivers/gpio/gpio-pca953x.c (line 190-192)
> >> It has double conversion there:
> >> 1. LE CPU: Read as LE and converted to LE (no-op), so, just u16
> >> 2. BE CPU: Read as BE and converted to LE, makes it __le16
> >> Looks like the conversion is not needed, only get_unaligned() is necessary.
> >> P.S. What about lines 244-245 there? I think they are no-op.
> >> Interesting that those two parts were added in quite different
> >> commits.
> > val = (u16)ret & 0xFF;
> > val = (u16)ret >> 8;
> > looks like cpu_to_be16()?
> cpu_to_le16(). No-op on LE CPU.
uhm yes of course.
> Perhaps they should be replaced by put_unaligned().
Makes sense to me.
Description: PGP signature