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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AF55AC433E0 for ; Thu, 28 May 2020 20:34:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9A5422088E for ; Thu, 28 May 2020 20:34:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2407294AbgE1Uee (ORCPT ); Thu, 28 May 2020 16:34:34 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:44194 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2407190AbgE1Uee (ORCPT ); Thu, 28 May 2020 16:34:34 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id C741C80307C1; Thu, 28 May 2020 20:34:30 +0000 (UTC) X-Virus-Scanned: amavisd-new at baikalelectronics.ru Received: from mail.baikalelectronics.ru ([127.0.0.1]) by localhost (mail.baikalelectronics.ru [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id jdv7qOIYXcJH; Thu, 28 May 2020 23:34:30 +0300 (MSK) Date: Thu, 28 May 2020 23:34:29 +0300 From: Serge Semin To: Andy Shevchenko CC: Serge Semin , Andy Shevchenko , Vinod Koul , Viresh Kumar , Dan Williams , Alexey Malahov , Thomas Bogendoerfer , Arnd Bergmann , Rob Herring , , devicetree , dmaengine , Linux Kernel Mailing List Subject: Re: [PATCH v3 08/10] dmaengine: dw: Add dummy device_caps callback Message-ID: <20200528203429.n23gi65zndfo4zti@mobilestation> References: <20200526225022.20405-1-Sergey.Semin@baikalelectronics.ru> <20200526225022.20405-9-Sergey.Semin@baikalelectronics.ru> <20200528145303.GU1634618@smile.fi.intel.com> <20200528152740.ggld7wkmaqiq4g6o@mobilestation> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On Thu, May 28, 2020 at 11:29:16PM +0300, Andy Shevchenko wrote: > On Thu, May 28, 2020 at 6:30 PM Serge Semin > wrote: > > > > On Thu, May 28, 2020 at 05:53:03PM +0300, Andy Shevchenko wrote: > > > On Wed, May 27, 2020 at 01:50:19AM +0300, Serge Semin wrote: > > > > Since some DW DMA controllers (like one installed on Baikal-T1 SoC) may > > > > have non-uniform DMA capabilities per device channels, let's add > > > > the DW DMA specific device_caps callback to expose that specifics up to > > > > the DMA consumer. It's a dummy function for now. We'll fill it in with > > > > capabilities overrides in the next commits. > > > > > > I think per se it is not worth to have it separated. Squash into the next one. > > > > bikeshadding? > > Actually no. > > > There is no any difference whether I add a dummy callback, then > > fill it in in a following up patch, or have the callback added together > > with some content. Let's see what Vinod thinks of it. Until then I'll stick with > > the current solution. > > The rule of thumb that we don't add dead code or code which is useless > per se. Go ahead and provide it with some usefulness. Actually yes. I've seen examples, which preparation patches first added prototypes with empty functionality, that in follow-up patches have been filled with a required code. I've seen Greg accepted such approach. So it's absolutely normal and acceptable. -Sergey > > -- > With Best Regards, > Andy Shevchenko