From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756480AbcLSWtr (ORCPT ); Mon, 19 Dec 2016 17:49:47 -0500 Received: from mout.gmx.net ([212.227.17.21]:55711 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750908AbcLSWtq (ORCPT ); Mon, 19 Dec 2016 17:49:46 -0500 Subject: Re: [PATCH 1/2] net: ethernet: sxgbe: remove private tx queue lock To: Pavel Machek References: <20161209112142.GA22710@amd> <20161211201104.GB20574@amd> <20161215210324.GA13878@amd> <6f43eac8-754b-cfa2-371d-050701deb4cd@gmx.de> <20161217173150.GA20231@amd> <20161218001507.GA5343@electric-eye.fr.zoreil.com> <20161218183010.GA7886@amd> Cc: Francois Romieu , bh74.an@samsung.com, ks.giri@samsung.com, vipul.pandya@samsung.com, peppe.cavallaro@st.com, alexandre.torgue@st.com, davem@davemloft.net, linux-kernel@vger.kernel.org, netdev@vger.kernel.org From: Lino Sanfilippo Message-ID: Date: Mon, 19 Dec 2016 23:49:25 +0100 User-Agent: Mozilla/5.0 (X11; Linux i686; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: <20161218183010.GA7886@amd> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K0:66TcKfi1KlvkYbF3De9OOan7o4p4I8Gk/gei/Ym00LdiBkwVtwL S/lp0UUxCRUt1FQzgaiWSSd0ig4BLOaxd3I0WmGjsZps+eDkQfoDj/Kj5mL08GRJ7V9cArz 9Snm/l2UvUqf5NOVNzUaa4vv0f7n4Fm8bG8K3oImvV+vQU5+xTCqimiSva7jymI7cDoccXE uiui3f2MKLZUyJel+AL4g== X-UI-Out-Filterresults: notjunk:1;V01:K0:+U6Scp/nK/Y=:i090wUkVjsVr+z7Fcs2IAi 5IfNv002nQKzIDxntYggMn+yQO2Dyb1E9BhRfXpH0xm+KPYHZ3K3gO1RKuIBpyTN/T6I7JP5d edClfCLEWeqDehjguUamb0hfsmUX6UL4HbbytLh40zevvSyBhOnAxpGImmiLPITksd5CpiWuj kLvVxcDSDK01yu6hC/N7Np/gF1US14K2CjinVYxmAIflheCfU0elH9Tty0n37SLY8emcAMLKF rMALNxklUVlIVpPwnYgB8Vg5amhFFUI1N1FN1XDcujRTYLpLt08kFv+JX+q0ucgPhNvvkfCFi 1QsQnwm01fobb8krrX6p8uRLlu5AFEtadCh1HxiUC3WhCQ8Eso04r5OdLQvVxc8eeSbY3izEU 3KfMYL0VcldDVZ8vsmJ24y6mXwVjcGdTf0HzT7RkiU0voB8acjw35bO/kzBfx5Las2h0/nP3Y QZVcFqV4WWEmJhaMLvTUXgrFg5L1/DvmmMeUrvqCqL0AiQuD9Ikza+sMzYDFplF57QSUTL96J Wsv2GBag6ak4usC4pld14QeswJb8ycnaa0fRK+U4CRTF+TO8myRoBowOXflad0jSuKfOMO7Tt aRCnKrcIibtE9MO60bkdss5ZWr1cSQUyZTZK4ASm5m1ZRjeanNel+KzAt3I/sYsRjQjHbOCHt mTakldpMrt3ks+XnsWfakCPsaTye0dIIx5ZZW5X1NXeFcijuKEwz/ASZiR3oidncxHM/rVROX KmLJQwrfIIJ2R/p8LP7WveaAlOeZawxCCN2ltLUNEQxr261y34LZw2XOMPP/8djwW5o4RO8DF 2/QNMF3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 18.12.2016 19:30, Pavel Machek wrote: > Hi! > >> > - e1efa87241272104d6a12c8b9fcdc4f62634d447 >> >> Yep, a sync of the dma descriptors before the hardware gets ownership of the tx tail >> idx is missing in the stmmac, too. > > I can reproduce failure with 4.4 fairly easily. I tried with dma_ > variant of barriers, and it failed, too > > [ 1018.410012] stmmac: early irq > [ 1023.939702] fpga_cmd_read:wait_event timed out! > [ 1033.128692] ------------[ cut here ]------------ > [ 1033.133329] WARNING: CPU: 0 PID: 0 at net/sched/sch_generic.c:303 > dev_watchdog+0x264/0x284() > [ 1033.141748] NETDEV WATCHDOG: eth0 (socfpga-dwmac): transmit queue 0 > timed out > [ 1033.148861] Modules linked in: This watchdog warning clearly says that for some reason the tx queue was stopped but never woken up in a certain timespan (5 sec in our case, which is a lot). Does this occur after the queue has been stopped and woken up again a few times or is it already the first time the queue is stopped (and never woken up)? Regards, Lino