Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756803Ab3DYIWS (ORCPT ); Thu, 25 Apr 2013 04:22:18 -0400 Received: from mail-ie0-f172.google.com ([209.85.223.172]:62694 "EHLO mail-ie0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756211Ab3DYIWO (ORCPT ); Thu, 25 Apr 2013 04:22:14 -0400 MIME-Version: 1.0 In-Reply-To: <1366279934-30761-6-git-send-email-lee.jones@linaro.org> References: <1366279934-30761-1-git-send-email-lee.jones@linaro.org> <1366279934-30761-6-git-send-email-lee.jones@linaro.org> Date: Thu, 25 Apr 2013 10:22:13 +0200 Message-ID: Subject: Re: [PATCH 05/32] dmaengine: ste_dma40: Supply macros to resolve 'src' and 'dst' directions From: Linus Walleij To: Lee Jones Cc: "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Rabin Vincent , Linus WALLEIJ , Arnd Bergmann , Vinod Koul , Per Forlin , Dan Williams Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1620 Lines: 44 On Thu, Apr 18, 2013 at 12:11 PM, Lee Jones wrote: > There are lots of lengthy if() statements located sporadically up and > down the driver. This simple macro should make many of them a little > simpler to decipher. The remainder have to stay in place, as they > detail slightly more specific settings. > > Cc: Vinod Koul > Cc: Dan Williams > Cc: Per Forlin > Cc: Rabin Vincent > Signed-off-by: Lee Jones (...) > +#define D40_IS_SRC(dir) ((dir == STEDMA40_PERIPH_TO_MEM) ? true : false) And when I reas the code and see D40_IS_SRC, what does that mean? That the channel is a source of .. what exactly? The older explicit comparison would be more informative. > +#define D40_IS_DST(dir) (((dir == STEDMA40_MEM_TO_PERIPH) || \ > + (dir == STEDMA40_MEM_TO_MEM)) ? true : false) > + The comparison to STEDMA40_MEM_TO_MEM is unintelligible, if I see that macro it has a very unintuitive name, since it is not just DST but also SRC. The latter macro would be named somthing like D40_IS_DST_OR_MEM2MEM and then it will not simplify the code very much. You need to come up with something different here, this is just making the driver harder to understand. I think this patch should be just dropped. Yours, Linus Walleij -- 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/