Return-path: Received: from caladan.dune.hu ([78.24.191.180]:59236 "EHLO arrakis.dune.hu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752537AbcCHM6H (ORCPT ); Tue, 8 Mar 2016 07:58:07 -0500 Subject: Re: About adding support for MT76x2U to Linux kernel To: Johannes Stezenbach References: <20150814081526.GC20192@hackpad.Elisa> <20150814143229.61440072@north> <20160302073210.GA31353@lakka.kapsi.fi> <20160307111443.GA7205@sig21.net> <56DD6B4F.2050405@openwrt.org> <20160307124103.GA22175@sig21.net> <56DDF11E.3060102@openwrt.org> <20160308124908.GA14746@sig21.net> Cc: =?UTF-8?Q?Tuomas_R=c3=a4s=c3=a4nen?= , =?UTF-8?Q?Jakub_Kici=c5=84ski?= , linux-wireless@vger.kernel.org, tuomasjjrasanen@opinsys.fi, Linus Walleij From: Felix Fietkau Message-ID: <56DECC5B.2090508@openwrt.org> (sfid-20160308_135824_911345_D1FFA4FD) Date: Tue, 8 Mar 2016 13:58:03 +0100 MIME-Version: 1.0 In-Reply-To: <20160308124908.GA14746@sig21.net> Content-Type: text/plain; charset=utf-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2016-03-08 13:49, Johannes Stezenbach wrote: > On Mon, Mar 07, 2016 at 10:22:38PM +0100, Felix Fietkau wrote: >> On 2016-03-07 13:41, Johannes Stezenbach wrote: >> > http://www.mediatek.com/en/downloads1/downloads/mt7612u/ >> I checked, they simply use a software timer for it and stuff buffered >> multicast packets into the BE queue. I don't think the hardware offers >> any better way of doing this... > > I had to refresh my memory on this driver. The thing that tripped > me when I first read through it was that is using a jiffies based > timer and additionally sets it to fire 10ms after the calculated > beacon time. So it's always too late, isn't it? > > But of course it is irrelevant for us since we can use a hrtimer. > However, if other frames are queued in the hw they are still sent > before the buffered frames. Since the hw has a dedicated queue > for HCCA I wonder if it could be used here? > (My knowledged of the standard is also rusty, ISTR the buffered > traffic must be sent before other traffic before the stations > go back to sleep.) On mt76x2e, I simply use the management queue for buffered frames, since it has a very high priority, and management frames are typically delivered via the voice WMM queue anyway. I think the MAC is probably similar enough that the same approach is possible on mt76x2u as well. - Felix