From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lin Ming Subject: Re: [PATCH 0/3] ata port runtime power management support Date: Thu, 03 Nov 2011 22:21:47 +0800 Message-ID: <1320330107.2813.73.camel@hp6530s> References: <1320214900-2112-1-git-send-email-ming.m.lin@intel.com> <20111102151711.GB12543@dhcp-172-17-108-109.mtv.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from mga14.intel.com ([143.182.124.37]:11306 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753201Ab1KCOWx (ORCPT ); Thu, 3 Nov 2011 10:22:53 -0400 In-Reply-To: <20111102151711.GB12543@dhcp-172-17-108-109.mtv.corp.google.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Tejun Heo Cc: "linux-kernel@vger.kernel.org" , "linux-ide@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "linux-pm@vger.kernel.org" , Alan Stern , Jeff Garzik , "Rafael J. Wysocki" , James Bottomley , "Huang, Ying" , "Zhang, Rui" On Wed, 2011-11-02 at 23:17 +0800, Tejun Heo wrote: > Hello, > > On Wed, Nov 02, 2011 at 02:21:37PM +0800, Lin Ming wrote: > > These 3 patches add ata port runtime pm support, which is done through scsi layer. > > scsi host runtime pm mechanism is already there(scsi_pm.c). > > These patches add hooks for ata port. > > > > Lin Ming (3): > > scsi: fix potential dead lock for host runtime pm > > scsi: add hooks for host runtime power management > > ata: implement ata port runtime pm hooks > > Hmmm.... Some questions. > > * How much does this add on top of hardware timed auto spindown and > dynamic link power management? Sorry, I don't understand this question. What do you mean? > > * Do the added benefits justify yet another runtime powersaving > mechanism? There will be ACPI firmware which supports ata port runtime D3Cold. To enable ata port runtime PM is the first step. > > * Any way we can tie the other stuff with overall runtime PM? What's the other stuff? Do you mean tie disk/link/port/controller stuff with overall runtime PM? I'm not sure for now. Need to think about it more.