From: Robert Hancock <hancockrwd@gmail.com>
To: JiSheng Zhang <jszhang3@gmail.com>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>,
linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org
Subject: Re: Do we need to implement sr START/STOP management
Date: Tue, 01 Nov 2011 19:13:16 -0600 [thread overview]
Message-ID: <4EB0992C.5070309@gmail.com> (raw)
In-Reply-To: <CADyp2Pdac=z6KzKnNykBCZNRLnjkv-z901Hwd-U0o2wB2qHWOA@mail.gmail.com>
On 11/01/2011 12:35 AM, JiSheng Zhang wrote:
> Hi James,
>
> 2011/11/1 James Bottomley<James.Bottomley@hansenpartnership.com>:
>> On Tue, 2011-11-01 at 13:31 +0800, JiSheng Zhang wrote:
>>> Currently, there's no start/stop management in scsi cdrom driver to
>>> spin up/down the motor do we need to implement it?
>>
>> Say more ... like what you think it buys. The auto spin down of a CD
>> tends to be the best power control we have and it's not even clear that
>> manufacturers have implemented any other useful power states.
>
> Does it mean the behavior depends on manufacturers? Some cd will spin
> down automatically? Even so, how about during shutdown just after reading
> something from cdrom?
>
> Thanks,
> Jisheng
I believe the main reason disks are stopped during shutdown is that for
many hard drives that use head unloading, it's much better for the
lifespan of the drive to do a powered head unload on software command
before powering off than an emergency unload caused by a loss of power.
I don't believe that optical drives have such an issue.
next prev parent reply other threads:[~2011-11-02 1:13 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-01 5:31 Do we need to implement sr START/STOP management JiSheng Zhang
2011-11-01 5:53 ` James Bottomley
2011-11-01 6:35 ` JiSheng Zhang
2011-11-01 12:35 ` James Bottomley
2011-11-02 1:13 ` Robert Hancock [this message]
2011-11-03 6:38 ` JiSheng Zhang
2011-11-03 14:38 ` Tejun Heo
2011-11-03 15:34 ` Douglas Gilbert
2011-11-03 15:46 ` Tejun Heo
2011-11-03 17:13 ` Douglas Gilbert
2011-11-03 21:04 ` Tejun Heo
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