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    SubjectRe: [rtc-linux] Re: [PATCH] rtc: Make rtc_update_irq callable with irqs enabled
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    On Fri, 24 Apr 2009 21:41:17 +0200, Alessandro Zummo <alessandro.zummo@towertech.it> 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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