Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753449AbZKPQnX (ORCPT ); Mon, 16 Nov 2009 11:43:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753424AbZKPQnW (ORCPT ); Mon, 16 Nov 2009 11:43:22 -0500 Received: from smtp-out.google.com ([216.239.45.13]:6589 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753326AbZKPQnU convert rfc822-to-8bit (ORCPT ); Mon, 16 Nov 2009 11:43:20 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=mime-version:in-reply-to:references:date:message-id:subject:from:to: cc:content-type:content-transfer-encoding:x-system-of-record; b=pKhuAh9VG+UdxEHP0EC2vcxHuE56qfZbDxRTexpXULoz/DOQaF1K6jTO8mtSMeobD 12BITam5MLa3QEbMLAL9g== MIME-Version: 1.0 In-Reply-To: <20091116163659.GB3568@n2100.arm.linux.org.uk> References: <20091102104949.GA23456@elf.ucw.cz> <20091116163659.GB3568@n2100.arm.linux.org.uk> Date: Mon, 16 Nov 2009 08:43:20 -0800 Message-ID: Subject: Re: [PATCH 2/3] msm: add minimal board file for HTC Dream device From: Brian Swetland To: Russell King - ARM Linux Cc: Pavel Machek , "Arve Hj?nnev?g" , kernel list , linux-arm-kernel Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1454 Lines: 38 On Mon, Nov 16, 2009 at 8:36 AM, Russell King - ARM Linux wrote: > On Mon, Nov 02, 2009 at 11:49:49AM +0100, Pavel Machek wrote: >> +MACHINE_START(TROUT, "HTC Dream") >> +#ifdef CONFIG_MSM_DEBUG_UART >> +     .phys_io        = MSM_DEBUG_UART_PHYS, >> +     .io_pg_offst    = ((MSM_DEBUG_UART_BASE) >> 18) & 0xfffc, >> +#endif > > Why is this ifdef'd?  Two reasons why not to do this: > > 1. MSM_DEBUG_UART is always defined, so the conditional is pointless For a default dream build, definitely, but not always on every msm7k target (some devices may not have a serial port that can safely be chattered at by the debug code). For this board file, no harm to require it. > 2. the low level page table building code does not expect these to be >   unset (or even set to an invalid value).  Leaving them unset and >   having DEBUG_LL enabled is a recipe to prevent booting. What's the best way to handle a situation where there is no valid debug uart? Could the arch/platform require DEBUG_LL be unset via Kconfig directives if it is configured in a way where there is no valid debug uart? > To put it another way, these two fields aren't optional. > Thanks, Brian -- 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/