Re: [-next PATCH 2/4] treewide: Use DEVICE_ATTR_RW

Greg Kroah-Hartman
2017-12-20T09:32:15Z

On Wed, Dec 20, 2017 at 01:24:44AM -0800, Joe Perches wrote:
> On Wed, 2017-12-20 at 10:34 +0200, Jarkko Nikula wrote:
> > On Tue, Dec 19, 2017 at 10:15:07AM -0800, Joe Perches wrote:
> > > Convert DEVICE_ATTR uses to DEVICE_ATTR_RW where possible.
> []
> > > diff --git a/sound/soc/omap/mcbsp.c b/sound/soc/omap/mcbsp.c
> []
> > > @@ -854,7 +854,7 @@ static ssize_t dma_op_mode_store(struct device *dev,
> > > return size;
> > > }
> > >
> > > -static DEVICE_ATTR(dma_op_mode, 0644, dma_op_mode_show, dma_op_mode_store);
> > > +static DEVICE_ATTR_RW(dma_op_mode);
> > >
> >
> > While I can ack this part here if it helps generic cleanup effort I
> > don't understart would it improve code readability in general? Mode 644
> > is clear and don't need any grepping but for DEVICE_ATTR_RW() I had to go
> > through all of these files in order to see what does it mean:

Yeah, 644 is "clear", but _RW() is even more clear. Ideally I want to
get rid of all of the "non-standard" users that set random modes of
sysfs files, as we get it wrong too many times. Using the "defaults" is
much better.

> Are you suggesting that device.h (as that is where
> DEVICE_ATTR and the other DEVICE_ATTR_<FOO> variants
> are #defined) should have better comments for the
> _<FOO> variants?
>
> > DEVICE_ATTR_RW: include/linux/device.h
> > __ATTR_RW: include/linux/sysfs.h
> > S_IWUSR: include/uapi/linux/stat.h
> > S_IRUGO: include/linux/stat.h
>
> btw: patch 1/4 of the series does remove the uses of
> S_<PERMS> from these macros in sysfs.h and converts
> them to simple octal instead.

Why you didn't send that patch to the sysfs maintainer is a bit odd... :)

I should be taking this whole series through my tree. Joe, thanks for
doing this in an automated way, I've been wanting to see this done for a
long time.

thanks,

greg k-h