From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [patch 0/3] AHCI Link Power Management Date: Thu, 14 Jun 2007 16:56:43 +0900 Message-ID: <4670F4BB.3060306@gmail.com> References: <20070611114600.7fca1c24.kristen.c.accardi@intel.com> <466DFDB5.9030901@gmail.com> <466E0642.5020506@linux.intel.com> <466E1D51.9070007@gmail.com> <20070613090430.GK13747@elf.ucw.cz> <20070613092607.4ddf0f79.kristen.c.accardi@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20070613092607.4ddf0f79.kristen.c.accardi@intel.com> Sender: linux-ide-owner@vger.kernel.org To: Kristen Carlson Accardi Cc: Pavel Machek , Arjan van de Ven , jeff@garzik.org, james.bottomley@steeleye.com, linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, Jens Axboe List-Id: linux-scsi@vger.kernel.org Kristen Carlson Accardi wrote: >>>>> I'm not sure about this. We need better PM framework to support >>>>> powersaving in other controllers and some ahcis don't save much >>>>> when only link power management is used, >>>> do you have data to support this? >>> Yeah, it was some Lenovo notebook. Pavel is more familiar with the >>> hardware. Pavel, what was the notebook which didn't save much power >>> with standard SATA power save but needed port to be completely turned off? >> Thinkpad x60. Some one Kristen probably used while developing the >> patch :-). > > Yes - that confirms my conclusion that the first patch just wasn't > done correctly - cause when I measure the power savings with a power > meter on the X60 with my patches I see ~ 1W. Hmmm... Could it be that the controller doesn't enter powersave state when SControl is written to? -- tejun