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From: Tejun Heo <tj@kernel.org>
To: Mark Lord <kernel@teksavvy.com>
Cc: Justin Maggard <jmaggard10@gmail.com>,
	Robert Hancock <hancockrwd@gmail.com>,
	linux-ide@vger.kernel.org
Subject: Re: Hotplug issue with Marvell 6121
Date: Thu, 11 Mar 2010 12:45:09 +0900	[thread overview]
Message-ID: <4B986745.305@kernel.org> (raw)
In-Reply-To: <4B98647C.6010604@teksavvy.com>

Hello,

On 03/11/2010 12:33 PM, Mark Lord wrote:
> On 03/10/10 21:32, Justin Maggard wrote:
>>
>> It's not the 1.5Gbps that is causing the problem.  It appears to be
>> the act of changing speeds.  I added "libata.force=3:1.5Gbps" to my
>> kernel command line, and hotplugs seemed to work fine on that port
>> (presumably due to the fact that libata EH won't change the link speed
>> limit if it's already at 1.5Gbps).  The other port on the controller
>> still had hotplug problems.  So everything seems to be pointing to the
>> Marvell controller having problems when you change speeds.
> ...
> 
> If it's like their non-AHCI controllers (sata_mv), then the chipset/phy
> could be very particular about the sequence/timing used when changing
> speeds.

BTW, if not allowing PHY speed adjustment is necessary, the correct
way to implement that is in ->port_start() by modifying
link->hw_sata_spd_limit.  But I really hope there's some other way to
solve this.

Thanks.

-- 
tejun

  reply	other threads:[~2010-03-11  3:45 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-10  0:51 Hotplug issue with Marvell 6121 Justin Maggard
2010-03-10 22:46 ` Justin Maggard
2010-03-11  0:53   ` Robert Hancock
2010-03-11  1:01     ` Tejun Heo
2010-03-11  2:32       ` Justin Maggard
2010-03-11  3:33         ` Mark Lord
2010-03-11  3:45           ` Tejun Heo [this message]
2010-03-11 18:42             ` Justin Maggard
2010-03-11 22:28               ` Tejun Heo

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