Message-ID: <3FCA2380.1050902@pobox.com>
Date: Sun, 30 Nov 2003 12:06:08 -0500
From: Jeff Garzik <jgarzik@pobox.com>
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To: Bartlomiej Zolnierkiewicz <B.Zolnierkiewicz@elka.pw.edu.pl>
CC: Jens Axboe <axboe@suse.de>, "Prakash K. Cheemplavam" <prakashkc@gmx.de>,
       marcush@onlinehome.de, linux-kernel@vger.kernel.org,
       eric_mudama@Maxtor.com
Subject: Re: Silicon Image 3112A SATA trouble
References: <3FC36057.40108@gmx.de> <3FCA1DD3.70004@pobox.com> <20031130165146.GY10679@suse.de> <200311301758.53885.bzolnier@elka.pw.edu.pl>
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Bartlomiej Zolnierkiewicz wrote:
> On Sunday 30 of November 2003 17:51, Jens Axboe wrote:
>>>Tangent:  My non-pessimistic fix will involve submitting a single sector
>>>DMA r/w taskfile manually, then proceeding with the remaining sectors in
>>>another r/w taskfile.  This doubles the interrupts on the affected
>>>chipset/drive combos, but still allows large requests.  I'm not terribly
>>
>>Or split the request 50/50.
> 
> 
> We can't - hardware will lock up.

Well, the constraint we must satisfy is

	sector_count % 15 != 1

(i.e. "== 1" causes the lockup)

Beyond that, any request ratio should be ok AFAIK...

	Jeff


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