From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Duan Subject: RE: FEC on i.MX 7 transmit queue timeout Date: Mon, 8 May 2017 02:13:25 +0000 Message-ID: References: <86b63ee28acfff3426c4a0bf72d848c1@agner.ch> <2bdd64ab-5644-e0a0-9bfe-b8dd2fca7abb@nxp.com> <80191e7c9df5871cd450f13b9ea47a10@agner.ch> <110a7a48649cfcbbee46340c230e9008@agner.ch> <46a27329-36df-1eaf-1321-24db037842fe@nxp.com> <20170505122330.GA23432@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Cc: Stefan Agner , "festevam@gmail.com" , "netdev@vger.kernel.org" , "netdev-owner@vger.kernel.org" To: Andrew Lunn Return-path: Received: from mail-db5eur01on0087.outbound.protection.outlook.com ([104.47.2.87]:48800 "EHLO EUR01-DB5-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750943AbdEHCN3 (ORCPT ); Sun, 7 May 2017 22:13:29 -0400 In-Reply-To: <20170505122330.GA23432@lunn.ch> Content-Language: en-US Sender: netdev-owner@vger.kernel.org List-ID: From: Andrew Lunn Sent: Friday, May 05, 2017 8:24 PM >To: Andy Duan >Cc: Stefan Agner ; festevam@gmail.com; >netdev@vger.kernel.org; netdev-owner@vger.kernel.org >Subject: Re: FEC on i.MX 7 transmit queue timeout > >> No, it is not workaround. As i said, quque1 and queue2 are for AVB >> paths have higher priority in transmition. > >Does this higher priority result in the low priority queue being starved? = Is that >why the timer goes off? What happens when somebody does use AVB. Are >we back to the same problem? This is what seems to make is sounds like a >work around, not a fix. > > Andrew Yes, queue0 may be blocked by queue1 and queue2, then the queue0 watchdog t= ime maybe triggered. If somebody use AVB quque1 and queue2, the remaining bandwidth is for queue= 0, for example, in 100Mbps system, quque1 cost 50Mbps bandwidth and queue2 = cost 50Mbps bandwidth for audio and video streaming, then queue0 (best effo= rt) has 0 bandwidth that limit user case cannot have asynchronous frames (= IP(tcp/udp)) on networking. Of course these is extreme case.=20 In essentially, asynchronous frames (IP) go queue0 for the original design= . To do these just implement .ndo_select_queue() callback in driver like fs= l tree. Regards, Andy