* Re: ->ack_intr in m68k IDE drivers [was: Re: [PATCH 2/5] ide: ->ide_dma_clear_irq() -> ->clear_irq()]
[not found] ` <200905222044.42688.bzolnier@gmail.com>
@ 2009-05-22 19:19 ` Sergei Shtylyov
2009-05-22 19:19 ` Sergei Shtylyov
1 sibling, 0 replies; 3+ messages in thread
From: Sergei Shtylyov @ 2009-05-22 19:19 UTC (permalink / raw)
To: Bartlomiej Zolnierkiewicz; +Cc: linux-m68k, linux-ide, linux-kernel
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
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: ->ack_intr in m68k IDE drivers [was: Re: [PATCH 2/5] ide: ->ide_dma_clear_irq() -> ->clear_irq()]
[not found] ` <200905222044.42688.bzolnier@gmail.com>
2009-05-22 19:19 ` Sergei Shtylyov
@ 2009-05-22 19:19 ` Sergei Shtylyov
1 sibling, 0 replies; 3+ messages in thread
From: Sergei Shtylyov @ 2009-05-22 19:19 UTC (permalink / raw)
To: Bartlomiej Zolnierkiewicz; +Cc: linux-m68k, linux-ide, linux-kernel
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 name.
> 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
^ permalink raw reply [flat|nested] 3+ messages in thread