Message-ID: <4CF014F8.9000700@teksavvy.com>
Date: Fri, 26 Nov 2010 15:13:44 -0500
From: Mark Lord <kernel@teksavvy.com>
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To: Tejun Heo <tj@kernel.org>
CC: Tobias Karnat <tobias.karnat@googlemail.com>, linux-ide@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: sata_sil24: external raid storage mistaken as port multiplier
References: <1290461073.12443.21.camel@Tobias-Karnat>	 <1290514125.28293.2.camel@Tobias-Karnat> <1290572588.24847.20.camel@Tobias-Karnat> <4CEFEC17.6060503@kernel.org>
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On 10-11-26 12:19 PM, Tejun Heo wrote:
> On 11/24/2010 05:23 AM, Tobias Karnat wrote:
>> Hi,
>>
>> I got it fixed by removing ATA_FLAG_PMP from the SIL24_COMMON_FLAGS.
>>
>> Could someone turn this into a module option?
>>
>> The external raid case might in fact has a built-in port multiplier,
>> but the case can only be configured as raid0 and raid1.
>>
>> I suspect that Linux tries to to access the drives separately, which fails.
>
> Hmmm... well, libata is just sending SRST w/ the port number set to 15
> and the device is reporting that it is a port multipler to that.
> Depending on configuration these devices don't work too well when
> commanded as a PMP device.  If you put it into JBOD mode, it will
> probably work fine.  I have no idea why it still reports as a PMP
> device when configured as a virtual device.
>
> That said, yeah, it probably would be a good idea to add a
> libata.force param.

How about some form of auto-detection instead?

-ml
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