Re: [PATCH 10/13] eeepc-laptop: compare proper return values in get_cpufv

[Darren Hart <dvhart@infradead.org>]

On Tue, Sep 16, 2014 at 11:40:37PM +0200, Frans Klaver wrote:
> On Tue, Sep 16, 2014 at 02:27:15PM -0700, Darren Hart wrote:
> > 
> > - When reading and writing sysfs device attribute files, avoid dependency
> >   on specific error codes wherever possible. This minimizes coupling to
> >   the error handling implemementation within the kernel.
> > 
> >   In general, failures to read or write sysfs device attributes shall
> >   propogate errors wherever possible. Common errors include, but are not
> >   limited to:
> > 
> >   -EIO: The read or store operation is not supported, typically returned by
> >         the sysfs system itself if the read or store pointer is NULL.
> > 
> >   -ENXIO: The read or store operation failed
> > 
> >   Error codes will not be changed without good reason, and should a change
> >   to error codes result in user-space breakage, it will be fixed, or the
> >   the offending change will be reverted.
> 
> sysfs-rules.txt is written for user space? In that case, reverting the
> change is as much a fix as patching it.
> 
> > 
> >   Userspace applications can, however, expect the format and contents of
> >   the attribute files to remain consistent in the absence of a version
> >   attribute change in the context of a given attributes.

Agreed, but I wanted to make this clear to kernel devs reading this as well,
rather than duplicating this blurb elsewhere.

> 
> ...attribute.
> 
> That's it for the nit-picking.

Thanks for the plural catch.

I'll send to Greg as a patch.

-- 
Darren Hart
Intel Open Source Technology Center