LKML Archive on
help / color / mirror / Atom feed
From: Sergei Shtylyov <>
To: Bartlomiej Zolnierkiewicz <>
Subject: Re: ->ack_intr in m68k IDE drivers  [was: Re: [PATCH 2/5] ide: ->ide_dma_clear_irq() -> ->clear_irq()]
Date: Fri, 22 May 2009 23:19:12 +0400	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

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

  reply	other threads:[~2009-05-22 19:18 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-08-19 18:31 [PATCH 2/5] ide: ->ide_dma_clear_irq() -> ->clear_irq() Bartlomiej Zolnierkiewicz
2008-08-19 22:22 ` Sergei Shtylyov
2008-09-15 22:11   ` Sergei Shtylyov
2008-09-15 22:29     ` Bartlomiej Zolnierkiewicz
2008-09-16  9:16       ` Sergei Shtylyov
2008-11-12  2:01         ` Jeremy Higdon
2009-05-21 14:07     ` Sergei Shtylyov
2009-05-22 18:44       ` ->ack_intr in m68k IDE drivers [was: Re: [PATCH 2/5] ide: ->ide_dma_clear_irq() -> ->clear_irq()] Bartlomiej Zolnierkiewicz
2009-05-22 19:19         ` Sergei Shtylyov [this message]
2009-05-22 19:19         ` Sergei Shtylyov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \ \ \ \ \ \ \

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).