From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: BQL support in gianfar causes network hickup Date: Sat, 24 Nov 2012 15:43:36 -0800 Message-ID: <1353800616.2590.4562.camel@edumazet-glaptop> References: <9AA65D849A88EB44B5D9B6A8BA098E23040A60D6EE6E@Exchange1.lawo.de> <50AFA599.9040108@windriver.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Tino Keitel Return-path: Received: from mail-ia0-f174.google.com ([209.85.210.174]:49256 "EHLO mail-ia0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752650Ab2KXXns (ORCPT ); Sat, 24 Nov 2012 18:43:48 -0500 Received: by mail-ia0-f174.google.com with SMTP id y25so7196296iay.19 for ; Sat, 24 Nov 2012 15:43:46 -0800 (PST) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Sat, 2012-11-24 at 20:42 +0000, Tino Keitel wrote: > Paul Gortmaker windriver.com> writes: > > > > > On 12-11-23 10:58 AM, Keitel, Tino (ALC NetworX GmbH) wrote: > > > Hi, > > > > > > commit d8a0f1b0af67679bba886784de10d8c21acc4e0e causes the following > > > trace on a Freescale RDB8313 board: > > > > Thanks for the report. > > > > > > > > NETDEV WATCHDOG: eth1 (fsl-gianfar): transmit queue 0 timed out > > > ------------[ cut here ]------------ > > > WARNING: > > > at /home/keitelt1/src/git/linux-stable/net/sched/sch_generic.c:255 > > > Modules linked in: > > > NIP: c02448b0 LR: c02448b0 CTR: c01c19b8 > > > REGS: c7ffbe40 TRAP: 0700 Not tainted (3.7.0-rc6-rt18) > > ^^^^^^^^^^^^^^^ > > I almost overlooked the above. It would have been nice to > > see more explicit information on what kernel you are running. > > I say that because the above concerns me. For several reasons. > > > > 1) it looks to be not mainline, but preempt_rt > > 2) There is no RT on 3.7 yet, so I'm assuming this is a custom > > forward port of the 250 odd RT patches. (The RT is 3.6.7-rt18, > > i.e. based on the 3.6 gregKH stable tree.) > > Sorry for the confusion. This was a 3.7.0-rc6 tree, and I forgot git clean after > trying the rt-patches and git reset --hard v3.7.0-rc6, so the localversion file > for -rt was still present, and the kernel was named 3.7.0-rc6-rt18. If I got > this right, this should be a normal kernel with just the version file modified. > > I tried kernel 3.3, which doesnt have the issue. I tried 3.4, 3.6.7 and 3.7-rc6, > which all show the kernel trace and ptp client misbehaviour. I tried 3.4, 3.6.7, > 3.7-rc6 and 3.6.5-rt18 with the patch I posted, and they were ok. > > The patch I posted is for 3.7-rc6. > Hmm, I wonder if BQL makes a particular bug showing more often. I see gianfar uses a very small watchdog_timeo of 1 second, while many drivers use 5 seconds. What happens if you change this to 5 seconds ? diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c index 19ac096..3a994f9 100644 --- a/drivers/net/ethernet/freescale/gianfar.c +++ b/drivers/net/ethernet/freescale/gianfar.c @@ -101,7 +101,7 @@ #include "gianfar.h" -#define TX_TIMEOUT (1*HZ) +#define TX_TIMEOUT (5*HZ) const char gfar_driver_version[] = "1.3";