From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B485C4321E for ; Thu, 24 Nov 2022 20:44:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229539AbiKXUoo convert rfc822-to-8bit (ORCPT ); Thu, 24 Nov 2022 15:44:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34984 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229450AbiKXUol (ORCPT ); Thu, 24 Nov 2022 15:44:41 -0500 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1990281F9A; Thu, 24 Nov 2022 12:44:39 -0800 (PST) Received: from ip5b412258.dynamic.kabel-deutschland.de ([91.65.34.88] helo=diego.localnet) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1oyJ59-0007px-11; Thu, 24 Nov 2022 21:44:27 +0100 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Conor Dooley , Conor Dooley Cc: Prabhakar , Paul Walmsley , Palmer Dabbelt , Albert Ou , Geert Uytterhoeven , Magnus Damm , Rob Herring , Krzysztof Kozlowski , Guo Ren , Jisheng Zhang , Atish Patra , Anup Patel , Andrew Jones , Nathan Chancellor , Philipp Tomsich , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, linux-renesas-soc@vger.kernel.org, Biju Das , Lad Prabhakar Subject: Re: [PATCH v4 1/7] riscv: asm: alternative-macros: Introduce ALTERNATIVE_3() macro Date: Thu, 24 Nov 2022 21:44:25 +0100 Message-ID: <3307993.NgBsaNRSFp@diego> In-Reply-To: <59aea5e5-25f1-de8c-9982-5db226f8bda5@kernel.org> References: <20221124172207.153718-1-prabhakar.mahadev-lad.rj@bp.renesas.com> <59aea5e5-25f1-de8c-9982-5db226f8bda5@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="iso-8859-1" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Donnerstag, 24. November 2022, 21:08:17 CET schrieb Conor Dooley: > On 24/11/2022 20:05, Conor Dooley wrote: > > EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > > > > On Thu, Nov 24, 2022 at 08:58:41PM +0100, Heiko Stübner wrote: > >> Am Donnerstag, 24. November 2022, 20:52:33 CET schrieb Conor Dooley: > >>> On Thu, Nov 24, 2022 at 05:22:01PM +0000, Prabhakar wrote: > >>>> From: Lad Prabhakar > >>>> > >>>> Introduce ALTERNATIVE_3() macro. > >>> > >>> Bit perfunctory I think! There's a lovely comment down below that would > >>> make for a better commit message if you were to yoink it. > >>> Content looks about what I'd expect to see though. > >> > >> Also both the comment on the original ALTERNATIVE_2 and the new ALTERNATIVE_3 > >> should probably be merged into a single comment explaining this once for all > >> ALTERNATIVE_x variants. > >> > >> Especially with the dma stuff, I'm pretty sure we'll get at least an ALTERNATIVE_4 > >> if not even more ;-) . So we defnitly don't want to repeat this multiple times. > > > > Oh I can promise you that there'll be a #4 ;) I do find the comment's > > wording to be quite odd though.. > > > >> + * A vendor wants to replace an old_content, but another vendor has used > >> + * ALTERNATIVE_2() to patch its customized content at the same location. In > > > > In particular this bit about "at the same location" does not make all > > that much sense. What "at the same location" means in this context > > should be expanded on imo. Effectively it boils down to someone else is > > already replacing the same things you want to replace - it's just the > > word "location" that might make sense if you're an old hand but not > > otherwise? > > Or maybe I am just biased because I tried to explain this to someone > recently and the language in the comments didn't make sense to them, > and anyone meddling with this code should be able to understand it? When I first looked at the whole alternatives / patching thing, the whole thing looked like dark magic to me ;-) . But yeah, the comment here, but also the original one above ALTERNATIVE_2 could use improvements to explain better what it tries to do. > >> + * this case, this vendor can create a new macro ALTERNATIVE_3() based > > > > Also, using the word "can". Is it not a "must" rather than a "can", > > since this stuff needs to be multiplatform? > > > >> + * on the following sample code and then replace ALTERNATIVE_2() with > >> + * ALTERNATIVE_3() to append its customized content. > > > > > >