Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754782Ab3HARaG (ORCPT ); Thu, 1 Aug 2013 13:30:06 -0400 Received: from mail-lb0-f171.google.com ([209.85.217.171]:49812 "EHLO mail-lb0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752077Ab3HARaE (ORCPT ); Thu, 1 Aug 2013 13:30:04 -0400 Message-ID: <51FA9B20.3080304@cogentembedded.com> Date: Thu, 01 Aug 2013 21:30:08 +0400 From: Sergei Shtylyov Organization: Cogent Embedded User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130620 Thunderbird/17.0.7 MIME-Version: 1.0 To: Alan Stern CC: boris brezillon , Greg Kroah-Hartman , Nicolas Ferre , Jean-Christophe Plagniol-Villard , Ludovic Desroches , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] USB: ohci-at91: add usb_clk for transition to common clk framework References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1096 Lines: 36 Hello. On 08/01/2013 07:56 PM, Alan Stern wrote: >>> What happens if uclk isn't found but it is needed? >> It will not fail but I guess the usb host won't work as the clock won't >> be correctly >> configured. >> I agree with you: this is not a good solution. >> Another option is to keep the previous version of this patch and put >> uclk handling >> in "#ifdef CONFIG_COMMON_CLK #endif" sections. >> Would this be acceptable ? > Yes. However, a more elegant approach is to protect the relevant > statements with: if (defined(CONFIG_COMMON_CLK)). This preprocessor You probably meant IS_ENABLED() or IS_BUIILTIN()? Or is there something I don't know about gcc preprocessor? > evaluates this to a 0 or 1, so the compiler will not generate output > for the protected source code if the symbol isn't defined. > Alan Stern WBR, Sergei -- 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/