From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-fx0-f158.google.com ([209.85.220.158]:34420 "EHLO mail-fx0-f158.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752162AbZDBFw2 (ORCPT ); Thu, 2 Apr 2009 01:52:28 -0400 Received: by fxm2 with SMTP id 2so342568fxm.37 for ; Wed, 01 Apr 2009 22:52:25 -0700 (PDT) To: Vivek Natarajan Cc: linux-wireless@vger.kernel.org Subject: Re: [PATCH] mac80211: Always send a null data frame if TIM bit is set. References: <20090302145030.GA4660@myhost.users.atheros.com> <8e92b4100903312115l2f013083jf507b66f8449a63a@mail.gmail.com> From: Kalle Valo Date: Thu, 02 Apr 2009 08:52:22 +0300 In-Reply-To: <8e92b4100903312115l2f013083jf507b66f8449a63a@mail.gmail.com> (Vivek Natarajan's message of "Wed\, 1 Apr 2009 09\:45\:10 +0530") Message-ID: <87ocvfiovd.fsf@litku.valot.fi> (sfid-20090402_075231_784877_7FBB0EC4) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-wireless-owner@vger.kernel.org List-ID: Vivek Natarajan writes: > Although the above patch is a right approach, it opens up an issue > with pspolling. > > In the above chunk of code, if the timeout is zero, instead of > sending a null frame to correct the state in the AP, we may keep on > sending ps poll frames ( And the ps state in the AP will never be > corrected) > > I have not tested pspolling with ath9k. But this seems to be an issue. > Thoughts? Maybe it's better to have a separate test for the case that TIM bit is set but we are not in power save and just send a nullfunc frame without psm bit. And leave the original power save code as it was. I really would like to have some frame ack callback to mac80211, even not all drivers support that. Otherwise we cannot reliably go to power save because the AP might not receive our nullfunc frame. I have to think about this and I'll try to propose something later on. -- Kalle Valo