Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932170Ab3COTOb (ORCPT ); Fri, 15 Mar 2013 15:14:31 -0400 Received: from mail-ie0-f172.google.com ([209.85.223.172]:52922 "EHLO mail-ie0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755415Ab3COTO3 (ORCPT ); Fri, 15 Mar 2013 15:14:29 -0400 MIME-Version: 1.0 In-Reply-To: References: <1460519.ejNFI1DrGk@vostro.rjw.lan> <1363280764.26318.4.camel@thor.lan> <5657408.cYX6iimiA4@vostro.rjw.lan> <5142E7F0.4020002@gmail.com> Date: Fri, 15 Mar 2013 12:14:28 -0700 X-Google-Sender-Auth: jvXDVVdWq2rAvgH3vhCFKmcyWrQ Message-ID: Subject: Re: [3.9-rc1] irq 16: nobody cared (was [3.9-rc1] very poor interrupt responses) From: Yinghai Lu To: Jiri Kosina Cc: Harald Arnesen , Kernel development list , "Rafael J. Wysocki" , Peter Hurley , Alan Stern , Thomas Meyer , Shawn Starr , USB list , linux-acpi@vger.kernel.org, Bjorn Helgaas , linux-pci@vger.kernel.org, Daniel Vetter , Imre Deak , Daniel Kurtz , dri-devel@lists.freedesktop.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1211 Lines: 29 On Fri, Mar 15, 2013 at 8:14 AM, Jiri Kosina wrote: > Just a datapoint -- I have put a trivial debugging patch in place, and it > reveals that "nobody cared" for irq 16 happens long after last > > I915_WRITE(GMBUS4 + reg_offset, 0); > > has been performed in gmbus_wait_hw_status(). On the other hand, if I > comment out both GMBUS4 register offset writes in gmbus_wait_hw_status(), > then it of course falls back to GPIO bit-banging, but the "nobody cared" > for irq 16 is gone. > > So it seems like something gets severely confused by the I915_WRITE to > GMBUS4 + reg_offset. So far this seems to have been reported solely on > Lenovos as far as I can see (although a completely different types), so it > might be some platform-specific quirk? > > Honestly, I still don't understand how all the GMBUS stuff relates to IRQ > 16 at all. that device is using i915 0000:00:02.0: irq 44 for MSI/MSI-X so can you try to boot with pci=nomsi? -- 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/