Re: Error in NCQ Command Handling in AHCI SATA

From: Tejun Heo
Date: Thu Oct 29 2009 - 10:19:40 EST


Hello, (cc list trimmed and linux-ide added)

DO NOT SPAM unrelated people.

Rashmi Mohapatra wrote:
> Please look at the log attached.
> Between line 1090 and 1210 something happens and the copy fails.
> If you look at Line No 1141 the log says,
>
> qc_complete_multiple ap->qc_active=ffff qc_active=fbfe done_mask=401
>
> Could it be possible that the software is issuing 32 commands MAX even
> if the Hardware supports less than that ?

Unlikely but then again you'll be the first to test an NCQ controller
with 16 command limit.

> Could it be a timeout issue for a block dma command ?
>
> Why the scsi error handler code is called ?
> Can someone point me to the code flow which ends up calling the Error
> Handler ?

Commands were issued but the controller didn't report completion
before the timeout expired (30s), so the EH kicked in. You have
multiple nobody cared warnings there. Does specifying "irqpoll"
kernel parameter make any difference?

--
tejun
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