On Fri, 12 Mar 2010 13:20:26 -0800 Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> wrote: > On Fri, Mar 12, 2010 at 09:57:43PM +0100, Florian Mickler wrote: > > On Fri, 12 Mar 2010 10:22:09 -0800 > > Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> wrote: > > > > > On Fri, Mar 12, 2010 at 07:03:08PM +0100, florian@xxxxxxxxxxx wrote: > > > > > > > > +static ssize_t rfkill_hard_show(struct device *dev, > > > > + struct device_attribute *attr, > > > > + char *buf) > > > > +{ > > > > + struct rfkill *rfkill = to_rfkill(dev); > > > > + unsigned long flags; > > > > + u32 state; > > > > + > > > > + spin_lock_irqsave(&rfkill->lock, flags); > > > > + state = rfkill->state; > > > > + spin_unlock_irqrestore(&rfkill->lock, flags); > > > > > > Why exactly is this lock needed? > > > > The rfkill state is updated from multiple contexts... Am I overlooking > > smth obvious here? > > > > You are not updating but reading... Are you concerned about seeing > a partial write to u32? It does not happen. > Hm.. You shure? On every arch that supports wireless drivers? I've just copied that code from the old sysfs state-file handler. So I assumed that reading partial updated state can happen... Also I just searched a little but did not find anything, cause i didn't know where to look. Who garantees this? Is it a gcc thing? -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html