Message-ID: <4C247C36.6040007@kernel.org>
Date: Fri, 25 Jun 2010 11:51:50 +0200
From: Tejun Heo <tj@kernel.org>
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To: Jeff Garzik <jeff@garzik.org>
CC: mingo@elte.hu, tglx@linutronix.de, bphilips@suse.de, yinghai@kernel.org,
       akpm@linux-foundation.org, torvalds@linux-foundation.org,
       linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org,
       stern@rowland.harvard.edu, gregkh@suse.de, khali@linux-fr.org
Subject: Re: [PATCH 11/12] libata: use IRQ expecting
References: <1276443098-20653-1-git-send-email-tj@kernel.org> <1276443098-20653-12-git-send-email-tj@kernel.org> <4C23F6C1.7070603@garzik.org> <4C245E50.7090701@kernel.org> <4C247B54.2050900@garzik.org>
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Hello,

On 06/25/2010 11:48 AM, Jeff Garzik wrote:
> My basic point is that you are implicitly changing the entire
> ata_qc_complete() API, and associated underlying assumptions.
> 
> The existing assumption, since libata day #0, is that ata_qc_complete()
> works entirely within the scope of a single qc -- thus enabling multiple
> calls for a single controller interrupt.  Your change greatly widens the
> scope to an entire port.

Yeah, I'm changing that and it actually reduces code.

> This isn't just an issue with sata_mv, that was just the easy example I
> remember off the top of my head.  sata_fsl and sata_nv also make the
> same assumption.  And it's a reasonable assumption, IMO.

Yeah, already updating all of them.

> I think an unexpect_irq() call is more appropriate outside
> ata_qc_complete().

The choices we have here are....

1. Update completion API so that libata core layer has enough
   information to decide expect/unexpect events.

2. Add expect/unexpect calls to individual drivers.

I think #1 is much better now and in the long run.  The code actually
looks better too.

Thanks.

-- 
tejun
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