Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757238Ab2BBTVU (ORCPT ); Thu, 2 Feb 2012 14:21:20 -0500 Received: from mail-vw0-f46.google.com ([209.85.212.46]:54130 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757214Ab2BBTVQ convert rfc822-to-8bit (ORCPT ); Thu, 2 Feb 2012 14:21:16 -0500 MIME-Version: 1.0 X-Originating-IP: [71.233.110.244] In-Reply-To: <4F27D9AD.1020806@pobox.com> References: <4E68A6E8.9020700@pobox.com> <20110908165155.f661a738.akpm@linux-foundation.org> <4F26B162.4050000@pobox.com> <4F274E28.2010200@gmail.com> <4F27D9AD.1020806@pobox.com> From: Edward Donovan Date: Thu, 2 Feb 2012 14:20:54 -0500 X-Google-Sender-Auth: MVyfuzoL6RPAC7wpgXvciByCh5g Message-ID: Subject: Re: ASM1083 PCIx-PCI bridge interrupts - widespread problems To: Chris Palmer Cc: Robert Hancock , torvalds@linux-foundation.org, Andrew Morton , Len Brown , ghost3k@ghost3k.net, linux-kernel@vger.kernel.org, keve@irb.hu, bjorn.ottervik@gmail.com, kaneda@freemail.hu, jeroen.vandenkeybus@gmail.com, clemens@ladisch.de Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4843 Lines: 131 (I'm just a bystander here, but interested, since I've been asked about it a few times) On Tue, Jan 31, 2012 at 7:08 AM, Chris Palmer wrote: > > On 31/01/2012 02:12, Robert Hancock wrote: >> On 01/30/2012 09:04 AM, Chris Palmer wrote: >>> Linus et al >>> >>> >>> For about 6 months many users have been having interrupt problems >>> with PCI boards, but it hasn't been >>> easy trying to find where the problem may be. However, it is now >>> looking likely that the problem lies >>> in the ASM1083 PCIe-PCI bridge chipset, as used by Asus in many >>> Sandybridge and AMD boards. >>> >>> My original bug report is: >>> ? ? ?https://bugzilla.kernel.org/show_bug.cgi?id=38632 ?(Sandybridge) >>> >>> and there several other similar ones. However there is also extensive >>> investigation in the following thread: >>> ? ? ?http://www.gossamer-threads.com/lists/linux/kernel/1466185 ?(AMD) >>> >>> There have also been reports of Windows users having similar problems. >>> >>> This problem prevents use of PCI boards in any motherboard with that >>> bridge chipset - including most >>> ASUS boards. At the moment though we don't know whether the chipset >>> or drivers are faulty, and if a >>> workaround is possible. >>> >>> At the moment my bug is assigned to drivers_network, but this doesn't >>> look appropriate. >>> >>> Hoping someone can help... >> >> If the analysis posted in the "Unhandled IRQs on AMD E-450" thread is >> correct, then it sounds like the bridge chip is delaying PCIe INTx >> deassert messages. In that case there isn't much the kernel is likely >> to be able to fix it properly, at least not without input from ASMedia >> or someone else with detailed knowledge of the chip. >> >> The workaround posted in that thread (switching to IRQ polling mode on >> the interrupt for some period of time after a screaming IRQ is >> detected) might be a workaround, but definitely would be considered a >> hack. >> >> Do you have a source/link for people having issues with this on >> Windows? I wouldn't be surprised though - I doubt Windows has any >> special handling for unhandled IRQs so likely it just hammers the IRQ >> handler until the IRQ gets deasserted. In that case the only thing a >> user might notice would be poor performance whenever the devices >> behind that bridge raise interrupts. >> > > Nothing definitive about Windows, but Edward found this discussion. It's > a bit emotive, but suggests the problem may be manifesting itself there too: > > http://forums.planetz.com/viewtopic.php?f=19&t=30557&sid=00d319732500eaf99c586b73060a9602 > > Chris If we end up helpless with this chip, will we at least warn the user that it's known to be buggy? I dont' know if there's a standard procedure when documenting bad hardware. I've CC'd a few more people who have reported this, and Clemens, who got to the bottom of it. Thanks, Ed >>> On 09/09/2011 00:51, Andrew Morton wrote: >>> >>>> On Thu, 08 Sep 2011 12:28:40 +0100 >>>> Chris Palmer ?wrote: >>>> >>>>> Andrew >>>>> >>>>> I'm writing to ask if you could cast a quick eye over the following >>>>> bugs, to give an opinion on where they should be assigned. Mine has >>>>> been >>>>> reassigned to Network Drivers but I'm not convinced that is right, >>>>> and I >>>>> think the problem is wider than that. >>>>> >>>>> In summary, interrupt handling for *PCI boards with ASUS Sandybridge >>>>> motherboards* seems to be broken. >>>>> >>>>> It has been seen with network and non-network PCI boards. PCIx network >>>>> boards work OK. And all reports are for ASUS motherboards. >>>>> >>>>> My bug report is >>>>> >>>>> https://bugzilla.kernel.org/show_bug.cgi?id=38632 >>>>> >>>>> Others that I know of are: >>>>> >>>>> https://bugzilla.redhat.com/show_bug.cgi?id=713351 >>>>> https://bugzilla.kernel.org/show_bug.cgi?id=35332 >>>>> https://bugzilla.kernel.org/show_bug.cgi?id=34242 >>>>> https://bugzilla.kernel.org/show_bug.cgi?id=32242 >>>>> https://bugzilla.kernel.org/show_bug.cgi?id=39122 >>>>> >>>>> >>>>> I'm now on kernel 3.0.4 with the problem still there. The only thing >>>>> that seems to make a difference is acpi=off (although one person >>>>> reported that it merely changed it from minutes to days before >>>>> occurring). >>>>> >>>>> I'd appreciate anything you could do to move this in the right >>>>> direction... >>>>> >>>> >>>> Most likely ACPI, I expect. ?I think that's >>>> acpi-config-interrupts@bugzilla.kernel.org. ?kernel.org DNS is dead at >>>> present and I can't check. >>>> >>>> Len, can you suggest how to triage these please? >> -- 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/