From: Aaron Lu <aaron.lu@intel.com>
To: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Alan Stern <stern@rowland.harvard.edu>,
Jeff Garzik <jgarzik@pobox.com>, Aaron Lu <aaron.lwe@gmail.com>,
Jack Wang <jack_wang@usish.com>,
Shane Huang <shane.huang@amd.com>,
Oliver Neukum <oliver@neukum.org>,
linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org,
linux-pm@vger.kernel.org, linux-acpi@vger.kernel.org
Subject: Re: [PATCH 1/2] scsi: sd: set ready_to_power_off for scsi disk
Date: Thu, 13 Sep 2012 16:23:29 +0800 [thread overview]
Message-ID: <50519801.6080502@intel.com> (raw)
In-Reply-To: <1347524092.2720.1.camel@dabdike.int.hansenpartnership.com>
On 09/13/2012 04:14 PM, James Bottomley wrote:
> On Thu, 2012-09-13 at 15:40 +0800, Aaron Lu wrote:
>> The ready_to_power_off flag is used to give indication to ATA layer
>> if this device's power can be removed when runtime suspended.
>>
>> This flag is determined by individual SCSI driver like sr, sd.
>>
>> This flag is introduced to support zero power ODD. When ODD
>> is runtime suspended, it may not be OK to remove its power.
>>
>> But for disk, it is always OK to be powered off, so set this flag.
>
> It is? I may have missed this, but where do you flush the cache of write
> back cache devices you're about to power off?
I suppose that is handled in sd_suspend callback, the power off happens
after a device is runtime suspended.
Thanks,
Aaron
next prev parent reply other threads:[~2012-09-13 8:23 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-13 7:40 [PATCH 0/2] Support runtime power off of HDD Aaron Lu
2012-09-13 7:40 ` [PATCH 1/2] scsi: sd: set ready_to_power_off for scsi disk Aaron Lu
2012-09-13 8:14 ` James Bottomley
2012-09-13 8:23 ` Aaron Lu [this message]
2012-09-13 8:37 ` James Bottomley
2012-09-13 8:49 ` Aaron Lu
2012-09-13 8:56 ` James Bottomley
2012-09-13 9:07 ` Aaron Lu
2012-09-13 9:26 ` James Bottomley
2012-09-13 10:16 ` Oliver Neukum
2012-09-13 10:51 ` James Bottomley
2012-09-13 12:34 ` Oliver Neukum
2012-09-13 16:24 ` Alan Stern
2012-09-13 20:18 ` Oliver Neukum
2012-09-13 20:46 ` Alan Stern
2012-09-14 6:57 ` Aaron Lu
2012-09-14 8:15 ` James Bottomley
2012-09-14 5:20 ` Aaron Lu
2012-09-14 8:17 ` James Bottomley
2012-09-14 8:48 ` Aaron Lu
2012-09-14 10:26 ` James Bottomley
2012-09-14 13:54 ` Aaron Lu
2012-09-17 15:01 ` Aaron Lu
2012-09-13 7:40 ` [PATCH 2/2] libata: acpi: set can_power_off for both ODD and HDD Aaron Lu
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