Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965818AbWKTNFE (ORCPT ); Mon, 20 Nov 2006 08:05:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965828AbWKTNFE (ORCPT ); Mon, 20 Nov 2006 08:05:04 -0500 Received: from caramon.arm.linux.org.uk ([217.147.92.249]:29963 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S965818AbWKTNFD (ORCPT ); Mon, 20 Nov 2006 08:05:03 -0500 Date: Mon, 20 Nov 2006 13:04:56 +0000 From: Russell King To: Alan Cc: Stefan Roese , linux-kernel@vger.kernel.org, linuxppc-embedded@ozlabs.org Subject: Re: [PATCH] serial: Use real irq on UART0 (IRQ = 0) on PPC4xx systems Message-ID: <20061120130455.GB22330@flint.arm.linux.org.uk> Mail-Followup-To: Alan , Stefan Roese , linux-kernel@vger.kernel.org, linuxppc-embedded@ozlabs.org References: <200611201200.36780.ml@stefan-roese.de> <20061120114248.60bb0869@localhost.localdomain> <200611201255.37754.ml@stefan-roese.de> <20061120121015.2fb667d0@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061120121015.2fb667d0@localhost.localdomain> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1271 Lines: 30 On Mon, Nov 20, 2006 at 12:10:15PM +0000, Alan wrote: > On Mon, 20 Nov 2006 12:54:32 +0100 (MET) > Stefan Roese wrote: > > Let's see, if I got this right. You mean that on such a platform, where 0 is a > > valid physical IRQ, we should assign another value as virtual IRQ number (not > > 0 and not -1 of course). And then the platform "pic" implementation should > > take care of the remapping of these virtual IRQ numbers to the physical > > numbers. > > > > Correct? > > Absolutely correct in all the detail. Since IRQ0 is not valid, can we arrange for the generic interrupt infrastructure to always fail it's allocation, and then remove the utterly unused bloatful irq_desc[0] ? Didn't think so since x86 folk would scream. Wait a moment, x86 can map IRQ0 to some other number for the timer interrupt, just like other architectures are being forced to map their UART interrupts. -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - 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/