From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH v9 07/10] block: add a new interface to block events Date: Sun, 18 Nov 2012 07:05:55 -0800 Message-ID: <20121118150555.GL7306@mtj.dyndns.org> References: <20121112192102.GG5560@mtj.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-pm-owner@vger.kernel.org To: Alan Stern Cc: Aaron Lu , Jeff Garzik , James Bottomley , "Rafael J. Wysocki" , Jeff Wu , Aaron Lu , linux-ide@vger.kernel.org, linux-pm@vger.kernel.org, linux-scsi@vger.kernel.org, linux-acpi@vger.kernel.org List-Id: linux-acpi@vger.kernel.org Hello, Alan. On Mon, Nov 12, 2012 at 02:34:01PM -0500, Alan Stern wrote: > It wouldn't do anything for the device, but it would allow the device's > parent to go to low power in between polls. That's why Aaron at one > point suggested lengthening the polling interval. Ah, okay. Entering and leaving suspend even every two seconds may save noticeable power for some controllers. Does that, tho, mean that the port would get reset every two seconds? If so (I can't see how else it would behave), it may not really work. I mean, you would be spending about ten seconds reinitiaizing everything and then enter sleep and do it all over again two seconds later, most likely wasting power in the process. Sounds weird to me. What am I missing? Thanks. -- tejun