From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTP id 8A802DE019 for ; Wed, 5 Mar 2008 19:30:36 +1100 (EST) Subject: Re: [BUG] 2.6.25-rc3-mm1 kernel panic while bootup on powerpc () From: Benjamin Herrenschmidt To: Andrew Morton In-Reply-To: <20080304103350.12d26560.akpm@linux-foundation.org> References: <20080304011928.e8c82c0c.akpm@linux-foundation.org> <47CD4AB3.3080409@linux.vnet.ibm.com> <20778.1204641656@neuling.org> <20080304103350.12d26560.akpm@linux-foundation.org> Content-Type: text/plain Date: Wed, 05 Mar 2008 19:23:40 +1100 Message-Id: <1204705420.21545.192.camel@pasglop> Mime-Version: 1.0 Cc: Matthew Wilcox , linuxppc-dev@ozlabs.org, Michael Neuling , linux-kernel@vger.kernel.org, Kamalesh Babulal Reply-To: benh@kernel.crashing.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, 2008-03-04 at 10:33 -0800, Andrew Morton wrote: > > Are we somehow enabling interrupts before we've setup > ppc_md.get_irq? > > > > Yes, we are - it's the semaphore rewrite which is doing this in > start_kernel(). It's being discussed. > > Enabling interrupts too early on powerpc was discovered to be fatal on > powerpc years ago. It looks like that remains the case. Yes, it is and will probably always be. All that semaphore mucking around that hard-enables interrupts is just asking for trouble (and on more than just powerpc... heh, how do you do if your main interrupt controller hasn't even been initialized yet ?) Ben. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762088AbYCEIas (ORCPT ); Wed, 5 Mar 2008 03:30:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752681AbYCEIak (ORCPT ); Wed, 5 Mar 2008 03:30:40 -0500 Received: from gate.crashing.org ([63.228.1.57]:40898 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752487AbYCEIaj (ORCPT ); Wed, 5 Mar 2008 03:30:39 -0500 Subject: Re: [BUG] 2.6.25-rc3-mm1 kernel panic while bootup on powerpc () From: Benjamin Herrenschmidt Reply-To: benh@kernel.crashing.org To: Andrew Morton Cc: Michael Neuling , Matthew Wilcox , linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, Kamalesh Babulal In-Reply-To: <20080304103350.12d26560.akpm@linux-foundation.org> References: <20080304011928.e8c82c0c.akpm@linux-foundation.org> <47CD4AB3.3080409@linux.vnet.ibm.com> <20778.1204641656@neuling.org> <20080304103350.12d26560.akpm@linux-foundation.org> Content-Type: text/plain Date: Wed, 05 Mar 2008 19:23:40 +1100 Message-Id: <1204705420.21545.192.camel@pasglop> Mime-Version: 1.0 X-Mailer: Evolution 2.12.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2008-03-04 at 10:33 -0800, Andrew Morton wrote: > > Are we somehow enabling interrupts before we've setup > ppc_md.get_irq? > > > > Yes, we are - it's the semaphore rewrite which is doing this in > start_kernel(). It's being discussed. > > Enabling interrupts too early on powerpc was discovered to be fatal on > powerpc years ago. It looks like that remains the case. Yes, it is and will probably always be. All that semaphore mucking around that hard-enables interrupts is just asking for trouble (and on more than just powerpc... heh, how do you do if your main interrupt controller hasn't even been initialized yet ?) Ben.