Return-path: Received: from charlotte.tuxdriver.com ([70.61.120.58]:49678 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751288AbZJLTQs (ORCPT ); Mon, 12 Oct 2009 15:16:48 -0400 Date: Mon, 12 Oct 2009 15:00:53 -0400 From: "John W. Linville" To: Reinette Chatre Cc: linux-wireless@vger.kernel.org, ipw3945-devel@lists.sourceforge.net, Ben Cahill Subject: Re: [PATCH 03/17 v2.6.32 and w-t] iwlwifi: turn off device when not used. Message-ID: <20091012190053.GD2794@tuxdriver.com> References: <1255119634-3060-1-git-send-email-reinette.chatre@intel.com> <1255119634-3060-5-git-send-email-reinette.chatre@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1255119634-3060-5-git-send-email-reinette.chatre@intel.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: On Fri, Oct 09, 2009 at 01:20:20PM -0700, Reinette Chatre wrote: > From: Ben Cahill > > In some cases (e.g. when mac80211 calls iwl_mac_stop() for suspend or user > no longer wants device active), device has not been going into low power state > via __iwl_down(). apm_ops.reset() does not put device into low power state; > instead it resets the device, then puts it into a powered-up state ready to be > re-loaded with uCode and re-started. This has needlessly warmed up user's > laptops and drained batteries. > > With current architecture in which mac80211 controls device up/down (including > resetting device after firmware errors), there is no need for apm_ops.reset() > any more; apm_ops.reset() is basically a combination of apm_ops.stop() and > apm_ops.init(). > > Instead, __iwl_down() now unconditionally places the device into a low-power > state via apm_ops.stop(). Device may be re-started via __iwl_up() calling > apm_ops.init() as soon as it may be needed (e.g. quickly for firmware errors), > but in the meantime, device will stop wasting energy. > > Note that, even in this low power state, if driver re-enables interrupts, > the device retains the ability to sense the hardware RF-KILL switch, and > (except for 3945) interrupt the host when it changes. > > Signed-off-by: Ben Cahill > Signed-off-by: Reinette Chatre It this a regression? Bug reference? John -- John W. Linville Someday the world will need a hero, and you linville@tuxdriver.com might be all we have. Be ready.