Return-path: Received: from purkki.adurom.net ([80.68.90.206]:56296 "EHLO purkki.adurom.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753721Ab2GANEq (ORCPT ); Sun, 1 Jul 2012 09:04:46 -0400 From: Kalle Valo To: Eliad Peller Cc: Johannes Berg , linux-wireless@vger.kernel.org Subject: Re: [PATCH] mac80211: don't require associated->beacon_ies for ps References: <1340610505-7713-1-git-send-email-eliad@wizery.com> <87395j4j3y.fsf@purkki.adurom.net> Date: Sun, 01 Jul 2012 16:04:44 +0300 In-Reply-To: (Eliad Peller's message of "Mon, 25 Jun 2012 16:54:39 +0300") Message-ID: <87txxr3a4z.fsf@purkki.adurom.net> (sfid-20120701_150449_826077_AB2A8394) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi Eliad, sorry for the late reply, I'm on vacation and enjoying Finland's great summer, 18 C and raining :) Eliad Peller writes: > On Mon, Jun 25, 2012 at 4:27 PM, Kalle Valo wrote: >>> beacon_ies is needed only in order to extract the dtim >>> period. However, even if it's missing we can still enter >>> ps with dtim=1 (which also happens if the TIM ie is invalid). >>> >>> Most drivers don't use conf.max_sleep_period/ps_dtim_period >>> anyway, and this check prevents them from entering ps if >>> they don't have beacon (but only probe response), even though >>> the beacon is not needed at all. >> >> Does this increase the chances of accidentally using dtim 1 even though >> AP has dtim > 1? I'm just worried that it's difficult to detect cases >> when we are forcing dtim to 1 and nobody might not notice it. How often >> will this happen? >> > doesn't dtim=1 is still better than not entering ps at all? > i think the only bad effect of using dtim=1 (instead of greater value) > is wrt power saving. but entering psm with dtim=1 is still better than > not entering psm at all. Sure. I was just thinking ahead and trying to avoid future problems (ie. accidentally using dtim=1). -- Kalle Valo