From: Tejun Heo <tj@kernel.org>
To: Mark Lord <kernel@teksavvy.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>,
Jeff Garzik <jeff@garzik.org>,
t.artem@mailcity.com,
"linux-ide@vger.kernel.org" <linux-ide@vger.kernel.org>
Subject: Re: ahci: CAP_SSS and parallel scan
Date: Fri, 07 May 2010 07:16:07 +0200 [thread overview]
Message-ID: <4BE3A217.2030407@kernel.org> (raw)
In-Reply-To: <4BE3244A.7060607@teksavvy.com>
On 05/06/2010 10:19 PM, Mark Lord wrote:
> On 06/05/10 03:49 PM, Jeff Garzik wrote:
>>
>>> Currently, there's no way to tell whether staggered spin up is needed
>>> or drives are already spun up.
>
> Perhaps by issuing a "CHECK POWER MODE" command?
> For many drives, a non-spinning drive is detectable from its IDENTIFY data.
Heh, yeah, I wish it were like that. IIRC, there are two different
staggered spin up scheme. The one implemented by CAP_SSS uses link
init sequence as signal to spin up which means you don't even know
whether there's a device attached before committing to spinning it up.
Gotta love ATA. :-)
--
tejun
prev parent reply other threads:[~2010-05-07 5:16 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-06 8:22 ahci: CAP_SSS and parallel scan Tejun Heo
2010-05-06 9:30 ` Arjan van de Ven
2010-05-06 14:44 ` Tejun Heo
2010-05-06 19:49 ` Jeff Garzik
2010-05-07 5:14 ` Tejun Heo
2010-05-07 21:33 ` Jeff Garzik
2010-05-08 8:40 ` Tejun Heo
2010-05-08 21:53 ` Jeff Garzik
2010-05-06 20:19 ` Mark Lord
2010-05-07 5:16 ` Tejun Heo [this message]
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