Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422828AbWLPXg7 (ORCPT ); Sat, 16 Dec 2006 18:36:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422830AbWLPXg6 (ORCPT ); Sat, 16 Dec 2006 18:36:58 -0500 Received: from smtp.osdl.org ([65.172.181.25]:53957 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422828AbWLPXg6 (ORCPT ); Sat, 16 Dec 2006 18:36:58 -0500 Date: Sat, 16 Dec 2006 15:36:38 -0800 (PST) From: Linus Torvalds To: Tobias Diedrich cc: Linux Kernel Mailing List , Andi Kleen , Yinghai Lu , "Eric W. Biederman" , Andrew Morton Subject: Re: IO-APIC + timer doesn't work (was: Linux 2.6.20-rc1) In-Reply-To: <20061216230605.GA2789@melchior.yamamaya.is-a-geek.org> Message-ID: References: <20061216174536.GA2753@melchior.yamamaya.is-a-geek.org> <20061216225338.GA2616@melchior.yamamaya.is-a-geek.org> <20061216230605.GA2789@melchior.yamamaya.is-a-geek.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1857 Lines: 51 On Sun, 17 Dec 2006, Tobias Diedrich wrote: > > With commit b0268726 backed out, 2.6.20-rc1 boots fine. Ok. It's sad, because that thing really did clean stuff up, and seemed like a nice and robust approach. Your dmesg is kind of interesting: ..TIMER: trying IO-APIC=0 PIN=0 with 8259 IRQ0 enabled(7)APIC error on CPU0: 04(40) .. failed where that APIC error on CPU0 seems to be a "Send accept error" and "Send illegal vector" thing. I think we actually got the interrupt there, but because we had some APIC setup bug, we didn't accept it properly, and it resulted in that "APIC error" thing. Maybe. This is a long shot, but I wonder if we should _wait_ for the APIC to stabilize after we've unmasked the IRQ. Ie, if you could undo the back-out (going back to the broken situation), and try the patch below, and see if it makes a difference. Unlikely, I know. I don't see anything wrong with the code, though, but maybe I'm just blind. Eric, Andi, Yinghai, do you see anything here to explain why that commit breaks? Linus --- diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c index 2a1dcd5..a8a09e0 100644 --- a/arch/x86_64/kernel/io_apic.c +++ b/arch/x86_64/kernel/io_apic.c @@ -294,7 +294,7 @@ static void add_pin_to_irq(unsigned int irq, int apic, int pin) DO_ACTION( __mask, 0, |= 0x00010000, io_apic_sync(entry->apic) ) /* mask = 1 */ -DO_ACTION( __unmask, 0, &= 0xfffeffff, ) +DO_ACTION( __unmask, 0, &= 0xfffeffff, io_apic_sync(entry->apic) ) /* mask = 0 */ static void mask_IO_APIC_irq (unsigned int irq) - 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/