Odd ada(4) failures when trying using USB scanner
Michael Reifenberger
mike at reifenberger.com
Mon Feb 1 14:40:48 UTC 2010
On Mon, 1 Feb 2010, Alexander Motin wrote:
> Date: Mon, 01 Feb 2010 14:18:17 +0200
> From: Alexander Motin <mav at FreeBSD.org>
> To: Michael Reifenberger <mike at reifenberger.com>
> Cc: FreeBSD-Current <freebsd-current at freebsd.org>
> Subject: Re: Odd ada(4) failures when trying using USB scanner
>
> Michael Reifenberger wrote:
>> I'm using -current as of r202157.
>>
>> When attaching an epson USB scanner and trying to `scanimage -L`
>> I get a freeze for some time and the following console logs:
>> ...
>> ata1: FAILURE - odd-sized DMA transfer attempt 5 % 2
>> ata1: setting up DMA failed
>
> I would say that scanner application tries to probe all CAM devices,
> looking for scanner. While doing it, it uses SCSI/ATAPI commands with
> odd-sized transfer sizes. It causes errors from ata(4) and triggers bug
> in IXP700 AHCI controller. Odd-sized requests are generally not
> supported by ATA/SATA. Second problem is in work now.
>
Could odd-sized commands be prohibited/ignored by the driver then?
Thanks for your work on ATA-CAM anyway!
Bye/2
---
Michael Reifenberger
Michael at Reifenberger.com
http://www.Reifenberger.com
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