Messages in this thread | | | Date | Fri, 22 May 2009 23:19:12 +0400 | From | Sergei Shtylyov <> | Subject | Re: ->ack_intr in m68k IDE drivers [was: Re: [PATCH 2/5] ide: ->ide_dma_clear_irq() -> ->clear_irq()] |
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Bartlomiej Zolnierkiewicz wrote:
>>>> It may also be worth considering turning this method into >>>>test-and-clear, so that we can get the actual IDE interrupt state on >>>>the chips that implement this...
>>> Probably might add the test_irq() method to be called on >>>!hwif->waiting_for_dma. Cleraing the status at once seems impractical...
>> Yet this seems what ack_intr() method is doing already... >> What it does is testing IRQ status and "acknowledging" it (the semantics >>of "acknowledge" is not clear to me, yet it seems that it's clearing the >>interrupt latch in the drivers where it's implemented). And the call site of >>ack_intr() method corresponds to where test_irq() should have been called, >>so it seems we don't need yet another method and probably didn't even need >>clear_irq() method in the first place?..
> They have different goals -- the main purpose of ack_intr() (despite its name) > seems to be testing whether the IRQ is ours,
It does clear some interrupt bit if it sees that IRQ is ours too, hence the same.
> OTOH in clear_irq() we know that > already and we just want to clear the pending IRQ status.
There seems to be duplication of functionality b/w ack_intr() and clear_irq() now...
> So I'm not sure if unification is desirable... though some improvements are > definitely possibly there (less confusing naming at least)...
>> Bart, could you clarify about how ack_intr() is supposed to work?
> Good question, m68k list would be the best place to look for an answer..
Well, I seem to have been able to infer it from the code...
MBR, Sergei
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