From mboxrd@z Thu Jan 1 00:00:00 1970 From: Radek Podgorny Subject: Re: via velocity trivial patch Date: Sun, 10 May 2009 23:06:31 +0200 Message-ID: <4A0741D7.1050509@podgorny.cz> References: <49F1A05A.8070802@podgorny.cz> <4A01FBF6.1090001@podgorny.cz> <20090507.150213.192379856.davem@davemloft.net> <4A04184E.5040507@podgorny.cz> <20090508192948.GA19016@electric-eye.fr.zoreil.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Return-path: Received: from 180.129.broadband3.iol.cz ([85.70.129.180]:33285 "EHLO home.podgorny.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750972AbZEJVGf (ORCPT ); Sun, 10 May 2009 17:06:35 -0400 Received: from [10.25.3.4] (simir.podoli.pjih.czf [10.25.3.4]) by home.podgorny.cz (Postfix) with ESMTP id 910B786560 for ; Sun, 10 May 2009 23:06:32 +0200 (CEST) In-Reply-To: <20090508192948.GA19016@electric-eye.fr.zoreil.com> Sender: netdev-owner@vger.kernel.org List-ID: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi Francois, Francois Romieu wrote: > Radek Podgorny : > [...] >> Anyway, I've verified this is really happening on my hardware when >> multiple via velocity devices share the same interrupt. The one the >> interrupt is for reads the correct ISR value, the others sometimes read >> 0 and sometimes 0xffffffff. I'm not educated enough to tell why. > > Your quad port network card includes its own pci bus, right ? > If so can you send a 'lspci -vt' of the host ? I don't know much about the card except for it's this model http://www.roc-noc.com/product.php?productid=55. The output of lspci follows: radek@europa ~ % sudo lspci -vt - -[0000:00]-+-00.0 Intel Corporation 82815 815 Chipset Host Bridge and Memory Controller Hub +-01.0-[0000:01]----00.0 NVidia / SGS Thomson (Joint Venture) Riva128 +-1e.0-[0000:02-03]--+-00.0-[0000:03]--+-08.0 VIA Technologies, Inc. VT6120/VT6121/VT6122 Gigabit Ethernet Adapter | | +-09.0 VIA Technologies, Inc. VT6120/VT6121/VT6122 Gigabit Ethernet Adapter | | +-0a.0 VIA Technologies, Inc. VT6120/VT6121/VT6122 Gigabit Ethernet Adapter | | \-0b.0 VIA Technologies, Inc. VT6120/VT6121/VT6122 Gigabit Ethernet Adapter | \-04.0 Intersil Corporation Prism 2.5 Wavelan chipset +-1f.0 Intel Corporation 82801BA ISA Bridge (LPC) +-1f.1 Intel Corporation 82801BA IDE U100 Controller +-1f.2 Intel Corporation 82801BA/BAM USB Controller #1 +-1f.3 Intel Corporation 82801BA/BAM SMBus Controller +-1f.4 Intel Corporation 82801BA/BAM USB Controller #1 \-1f.5 Intel Corporation 82801BA/BAM AC'97 Audio Controller >> Reasons to include the fix: >> 1) Someone smarter than me suggested it (Jeff Garzik). >> 2) Fixed my problem. >> 3) Does not introduce a new problem. > > 3. probably stands: there is no reason for the driver to see a > 0xffffffff interupt status register (hardware fault or unplug apart). > > Well, almost: > > $ grep mac.*isr drivers/net/via-velocity.h > #define mac_read_isr(regs) readl(&((regs)->ISR)) > #define mac_write_isr(regs, x) writel((x),&((regs)->ISR)) > #define mac_clear_isr(regs) writel(0xffffffffL,&((regs)->ISR)) > > I can figure that there is a window through which the 2nd, 3rd and 4th > devices can read a 0xffffffff when they are brought up but it should > not be noticeable after this stage (and it may happen on the 1st device > as well if it shares its interrupt with some other device). > > Does it match your experience ? Well I haven't done any extensive data gathering (how often the 0xffffffff situation happens and so on) because I've found a way way to fix (workaround?) it and unfortunately it's a production machine. But, if you have any suggestions on what I shall do to help you debug it, please let me know. I can do some tests for short periods of time during a day. > >> So I'm attaching the patch again. Now with the proper sign-off. > > davem's life is probably simpler if you do not include anything > after the patch. > Thanks for the info. I don't mean to complicate things. Radek Podgorny -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.11 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkoHQdYACgkQ7mej6pjlbYQOYgCgoe19dnfkh74del3hXODGPEM1 RqYAn05j7ysqpJykjxyGdHsMB3x6FkV7 =bUxK -----END PGP SIGNATURE-----