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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 14583C433E2 for ; Thu, 21 May 2020 15:56:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E7B0B2072C for ; Thu, 21 May 2020 15:56:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dngjX3Te" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729667AbgEUP4x (ORCPT ); Thu, 21 May 2020 11:56:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40406 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728093AbgEUP4x (ORCPT ); Thu, 21 May 2020 11:56:53 -0400 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E4C71C061A0E; Thu, 21 May 2020 08:56:52 -0700 (PDT) Received: by mail-pf1-x441.google.com with SMTP id x15so3529024pfa.1; Thu, 21 May 2020 08:56:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=YLjdHqDrd9wWktm9zc7kw926gJ/JO0FqXQQJQmrShF4=; b=dngjX3TeyNGA7sZM07y2jXFvvj1nmwPK5g8vLMbECNPRlMxTkgVDBCfRCm4xl/ZlPj l/gcF3rw74gdyfv3+GS++6F7GPZw+ufPa7T0RDiDlmgCuZBohxaJOeqBBAM19QW/Xu7a SZcyBeTokj5OhtoJ4ZTWiW6unl0K0rsEhLyixrl3PCsNs8LCtaQ1/BG1tIwuCWAvmgCC WwKIx0A+Pznggn96M82Rly1BHnJn1lNA+k7uEtAUl2o4Na0QoUw9+tDRjCyuPofuBx5H pKMdpjVcSG259KqzVsGPR5a9Cvuj8+bpfkP3zYPA+gQgZ70yB1Ma0eNTBWAb34NZjov6 PtCg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=YLjdHqDrd9wWktm9zc7kw926gJ/JO0FqXQQJQmrShF4=; b=OzA00lIoS6txj72EcIRLkz859VpSlV9r++5ySqf9/bJuwSkGvMjBUJ2nM6JYdmVSmN wFFdq7Xh2VF42EmfUUCPoU2qb9M1q4PR8UyIbQJvEySeb0e1gAFM+OxsCJ/Kqn7ATzaN /aCRPcTmEgHNKO/duHtjE5xXcX8CuNeF8uIQ/uCJKA9w73GcQ/BRzYHnIQbW0/xI8pAn 8qCqLBF7Bku8MVZloOp92/2j5I+fEpc40dAZB1T67/ie1HnkUGLitE/s75Am0lTQCXHf zIl2UA6E4+t4DmcfwUCF6GzVamOMlb3OwADvpzIvl0EcwVVoort4xh/Peg+TH/TMk+sA rKWw== X-Gm-Message-State: AOAM532TNNKFlap9eFiBXCTSdxaGPLZDBrha3u7kzcs00Z/7pSHRjl2u pp966j3i82Om0Y42P1m57fEbL0EggYiG3i9h9hbS+OFkjAk= X-Google-Smtp-Source: ABdhPJwY6fukj1moTBQBXDZlJMalh9K/lPhnjO7xxB26LRgOQffMoS4rcujl+Hw/ssJOO8QGT/pGOV5trEVGneTgPgs= X-Received: by 2002:a62:2f43:: with SMTP id v64mr9786031pfv.170.1590076612340; Thu, 21 May 2020 08:56:52 -0700 (PDT) MIME-Version: 1.0 References: <20200521012206.14472-1-Sergey.Semin@baikalelectronics.ru> <20200521012206.14472-4-Sergey.Semin@baikalelectronics.ru> <20200521121228.aqplh6eftylnys3p@mobilestation> <20200521155143.GE4770@sirena.org.uk> In-Reply-To: <20200521155143.GE4770@sirena.org.uk> From: Andy Shevchenko Date: Thu, 21 May 2020 18:56:40 +0300 Message-ID: Subject: Re: [PATCH v3 03/16] spi: dw: Discard static DW DMA slave structures To: Mark Brown Cc: Serge Semin , Serge Semin , Georgy Vlasov , Ramil Zaripov , Alexey Malahov , Thomas Bogendoerfer , Paul Burton , Ralf Baechle , Andy Shevchenko , Arnd Bergmann , Rob Herring , linux-mips@vger.kernel.org, devicetree , Thomas Gleixner , Wan Ahmad Zainie , Jarkko Nikula , Clement Leger , linux-spi , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 21, 2020 at 6:51 PM Mark Brown wrote: > On Thu, May 21, 2020 at 03:12:28PM +0300, Serge Semin wrote: > > > Well, for me both solutions are equal except mine consumes less stack memory. > > The only reason why your solution might be better is that if DW DMA driver or > > the DMA engine subsystem changed the dw_dma_slave structure instance passed to > > the dma_request_channel() method, which non of them do. So I'll leave this for > > Mark to decide. Mark, could you give us your final word about this? > > Honestly I'm struggling to care either way. I guess saving a bit of > stack is potentially useful. Yes, but OTOH dropping maintainability by this is worse in my opinion. -- With Best Regards, Andy Shevchenko