Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764494AbYJJVfk (ORCPT ); Fri, 10 Oct 2008 17:35:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760626AbYJJVf3 (ORCPT ); Fri, 10 Oct 2008 17:35:29 -0400 Received: from ppp-111-109.adsl.restena.lu ([158.64.111.109]:40273 "EHLO bonbons.gotdns.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1763468AbYJJVf2 (ORCPT ); Fri, 10 Oct 2008 17:35:28 -0400 X-Greylist: delayed 478 seconds by postgrey-1.27 at vger.kernel.org; Fri, 10 Oct 2008 17:35:27 EDT Date: Fri, 10 Oct 2008 23:27:24 +0200 From: Bruno =?UTF-8?B?UHLDqW1vbnQ=?= To: "Alex Bennee" Cc: linux-kernel@vger.kernel.org, Francois Romieu Subject: Re: rtl8169_get_stats seems to be adding random crap to rx_missed_errors count Message-ID: <20081010232724.1447f915@neptune.home> In-Reply-To: References: X-Mailer: Claws Mail 3.5.0 (GTK+ 2.12.11; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3978 Lines: 98 Hi Alex, This issue has already been reported in http://lkml.org/lkml/2008/10/9/235 and a patch exists. Could you verify that patch #0009 at URL below fixes the issue for you: http://userweb.kernel.org/~romieu/r8169/2.6.27-rc9/20081007/ Bruno On Fri, 10 October 2008 "Alex Bennee" wrote: > Hi, > > I've been seeing odd behaviour in the ifconfig output for my rtl8169 > based network device. The ifconfig output had a very high number of > dropped packets in the display which changed massively every time I > checked. I tracked it down to /proc/net/dev and the a few test patches > it seems the rc_missed field is the culprit. I did a test patch of the > form: > > +++ b/drivers/net/r8169.c > @@ -3062,10 +3062,16 @@ static struct net_device_stats > *rtl8169_get_stats(struct net_device *dev) > unsigned long flags; > > if (netif_running(dev)) { > + u32 missed; > spin_lock_irqsave(&tp->lock, flags); > - dev->stats.rx_missed_errors += RTL_R32(RxMissed); > + missed = RTL_R32(RxMissed); > RTL_W32(RxMissed, 0); > spin_unlock_irqrestore(&tp->lock, flags); > + > + dev->stats.rx_missed_errors += missed; > + if (missed) > + printk(KERN_INFO "rtl8169_get_stats added %d > to missed count\n", missed); > + > } > > return &dev->stats; > > And low and behold I see this behaviour: > > [ 946.160188] rtl8169_get_stats added 250834943 to missed count > [ 946.160354] rtl8169_get_stats added 20768 to missed count > [ 946.160411] rtl8169_get_stats added 7032 to missed count > [ 946.160425] rtl8169_get_stats added 1677 to missed count > [ 946.160439] rtl8169_get_stats added 1577 to missed count > [ 946.160452] rtl8169_get_stats added 1543 to missed count > [ 946.160465] rtl8169_get_stats added 1517 to missed count > [ 946.160479] rtl8169_get_stats added 1572 to missed count > [ 946.160492] rtl8169_get_stats added 1586 to missed count > [ 946.160504] rtl8169_get_stats added 1284 to missed count > [ 948.164206] rtl8169_get_stats added 250864594 to missed count > [ 948.164374] rtl8169_get_stats added 21004 to missed count > [ 948.164434] rtl8169_get_stats added 7385 to missed count > [ 948.164447] rtl8169_get_stats added 1631 to missed count > [ 948.164461] rtl8169_get_stats added 1574 to missed count > [ 948.164475] rtl8169_get_stats added 1645 to missed count > [ 948.164489] rtl8169_get_stats added 1583 to missed count > [ 948.164503] rtl8169_get_stats added 1561 to missed count > [ 948.164523] rtl8169_get_stats added 2314 to missed count > [ 948.164534] rtl8169_get_stats added 1300 to missed count > [ 950.168182] rtl8169_get_stats added 250857857 to missed count > [ 950.168345] rtl8169_get_stats added 20465 to missed count > [ 950.168401] rtl8169_get_stats added 6903 to missed count > [ 950.168416] rtl8169_get_stats added 1711 to missed count > [ 950.168430] rtl8169_get_stats added 1585 to missed count > [ 950.168443] rtl8169_get_stats added 1532 to missed count > [ 950.168456] rtl8169_get_stats added 1520 to missed count > [ 950.168469] rtl8169_get_stats added 1539 to missed count > [ 950.168483] rtl8169_get_stats added 1588 to missed count > [ 950.168494] rtl8169_get_stats added 1282 to missed count > > It looks very much like the number being read is a decreasing counter > rather than anything else. > > Has anyone got a copy of the data sheet and can confirm that: > > RxMissed = 0x4c, > > is the correct offset for the register and it doesn't need any special > handling to be read? > > > > > -- > Alex, homepage: http://www.bennee.com/~alex/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/