Re: [PATCH 2/2] enhance /sys/class/rfkill//state interface

Florian Mickler
2010-02-20T23:07:21Z

On Sat, 20 Feb 2010 23:14:48 +0100
Johannes Berg <johannes@sipsolutions.net> wrote:

> On Sat, 2010-02-20 at 22:40 +0100, florian@mickler.org wrote:
> > Introduce a new state-value RFKILL_STATE_SOFT_AND_HARD_BLOCKED
> > which is returned only through the sysfs state file.
> > The other interfaces are designed so that they don't need this extra
> > state.
> >
> > This allows the sysfs to represent all possible states an rfkill
> > driver can
> > have.
> >
> > Signed-off-by: Florian Mickler <florian@mickler.org>
> > ---
> >
> > After stumbling over this arbitrary limitation of
> > sys/class/rfkill/*/state I
> > wondered what would hinder this patch?
>
> This is not backward compatible, so can't be done.
>
> johannes

hmm... ah, i see... if driver is in hard'n'soft-block state
an userspace program would expect to read hardblock instead of the
new hard'n'softblock-state...
now that i think of it, it even becomes obvious :)

cheers,
Flo