Messages in this thread | | | Date | Fri, 12 Mar 2010 13:20:26 -0800 | From | Dmitry Torokhov <> | Subject | Re: [PATCH 2/2] enhance sysfs rfkill interface |
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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@gmail.com> wrote: > > > On Fri, Mar 12, 2010 at 07:03:08PM +0100, florian@mickler.org 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.
-- Dmitry
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