From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mga09.intel.com ([134.134.136.24]:10512 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755005Ab2AIBhm (ORCPT ); Sun, 8 Jan 2012 20:37:42 -0500 Subject: Re: [PATCH RFC] iwlwifi: add basic runtime PM support From: "Guy, Wey-Yi" To: "Yan, Zheng" Cc: Johannes Berg , ilw@linux.intel.com, "netdev@vger.kernel.org" , linux-wireless In-Reply-To: <4F0A3C62.6010403@intel.com> References: <4F065F59.2070107@intel.com> <1325843269.3330.4.camel@jlt3.sipsolutions.net> <4F0A3C62.6010403@intel.com> Content-Type: text/plain; charset="UTF-8" Date: Sun, 08 Jan 2012 16:34:11 -0800 Message-ID: <1326069251.13074.360.camel@wwguy-huron> (sfid-20120109_023751_014283_49868169) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, 2012-01-09 at 09:01 +0800, Yan, Zheng wrote: > On 01/06/2012 05:47 PM, Johannes Berg wrote: > > [add linux-wireless] > > > > On Fri, 2012-01-06 at 10:41 +0800, Yan, Zheng wrote: > >> This simple patch adds open/close based runtime PM support to the iwlwifi driver. > >> Namely, make the driver suspend the device after shutting down the interface and > >> resume the device when activating the interface. In my test, suspending the device > >> can save about 0.4 watt power. The shortcoming is that the device no longer generate > >> rfkill changes interrupt. > > > > NACK due to that last sentence. There's no way we can live with that in > > the general case -- and your patch isn't even configurable afaict. And > > I'm sure polling the rfkill flag would use just as much energy. > > > It's configurable, runtime PM is disabled by default. Somehow I miss it, how you configure it? > > > There might be some value in this in a system that doesn't have a hard > > rfkill line, but that means this needs to be configurable since the > > device can't know whether there's a button or not [1]. > > > The patch targets system that only use software rfkill How you control that? Wey >