Messages in this thread | | | Date | Sun, 16 Aug 2009 16:25:13 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: Threaded interrupt handlers broken? |
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On Sun, 16 Aug 2009, Michael Buesch wrote: > On Sunday 16 August 2009 15:22:29 Thomas Gleixner wrote: > > > > + if (0&&unlikely(desc->status & IRQ_DISABLED)) { > > > > So the interrupt is marked disabled. How do you setup the handler > > ? And what does the primary handler do ? Can you post your driver > > code please? > > This patch converts the b43 driver to threaded interrupts: > http://bu3sch.de/patches/wireless-testing/20090816-1535/patches/002-b43-threaded-irq-handler.patch
On the first glance this looks not too bad. the unlocked access to the irq status registers looks a bit scary, but that is not relevant for the problem at hand.
> It kind of works with this hack applied to kernel/irq/manage.c
Hmm. Is the interrupt of the device shared ? If yes, what's the other device on that interrupt line ? what puzzles me is the fact that the IRQ_DISABLED flag is set. Is there anything unusual in dmesg ?
> > So you wake when the thread counter is != 0 after the decrement. > > > > #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) > > Yeah, isn't that what we want to do? I read the test as "wake other threads, > if there are other threads" or something like that.
No, it's for synchronize_irq(). When there are threaded handlers in progress, then sychronize_irq() waits on the waitqueue until they are finished. So we wake the queue when the last threaded handler of this irq line returns from thread_fn.
Thanks,
tglx
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