Re: [rtc-linux] Re: [PATCH] rtc: Make rtc_update_irq callable withirqs enabled

[Atsushi Nemoto]

On Fri, 24 Apr 2009 21:41:17 +0200, Alessandro Zummo <alessandro.zummo@xxxxxxxxxxxx> wrote:
> >  RTC alarm interrupt handler takes rtc->irq_lock by spin_lock()
> > > 2. A timer interrupt handler calls rtc_uie_timer() for UIE emulation
> > > 3. rtc_uie_timer() waits on rtc->irq_lock .... deadlock!  
> > 
> > Oops, this is wrong.  This deadlock cannot happen since
> > rtc_uie_timer() will be called in bh (softirq) context, not interrupt
> > context.
> 
>  Correct.
> 
>  And we have only one irq handler per driver. Anything else?

Some drivers (omap, pxa, etc.) have multiple irq handler.  Currently
all such drivers use IRQF_DISABLED so I do not see any real problem
now.

So I think my patch is rather "cleanup and bulletproof" than "bugfix".

---
Atsushi Nemoto
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