Re: [PATCH 11/12] libata: use IRQ expecting

From: Tejun Heo
Date: Fri Jun 25 2010 - 03:45:16 EST


Hello, Jeff.

On 06/25/2010 02:22 AM, Jeff Garzik wrote:
>> @@ -4972,6 +4972,8 @@ void ata_qc_complete(struct ata_queued_cmd *qc)
>> {
>> struct ata_port *ap = qc->ap;
>>
>> + unexpect_irq(ap->irq_expect, false);
>> +
>> /* XXX: New EH and old EH use different mechanisms to
>> * synchronize EH with regular execution path.
>> *
>
> Unconditional use of unexpect_irq() here seems incorrect for some cases,
> such as sata_mv's use, where ata_qc_complete() is called multiple times
> rather than a singleton ata_qc_complete_multiple() call.

Indeed, sata_mv is calling ata_qc_complete() directly multiple times.
I still think calling unexpect_irq() from ata_qc_complete() is correct
as ata_qc_complete() is always a good indicator of completion events.
What's missing is a way for sata_mv to indicate that it has more
events to expect for, which under the current implementation only
sata_mv interrupt handler can determine. I'll see if I can convert it
to use ata_qc_complete_multiple() instead.

Thanks.

--
tejun
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