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=-2.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 72DBCC47255 for ; Mon, 11 May 2020 11:58:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 52B4C214DB for ; Mon, 11 May 2020 11:58:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589198300; bh=I7c/5QR0NUZxXyJ3bfQU4K67hU6vugawyRi1MoWi3Ag=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ejCNXzmZjnveHFs1UE517MSu/MnnougLi9aMHybUnT9i/mnWjcA4h9SBNFLZJGkNa 26RmyWBSAO76eZY0yZXdCvO1Esu6EzmMMAoPUIh4Y/DZrK65hkN7QUgQ1lNLi9RMZO 5gSPlMhW2pVPcv67vXPnSYvhLcwR3lSr0rV36UnI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729475AbgEKL6R (ORCPT ); Mon, 11 May 2020 07:58:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:41716 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726068AbgEKL6R (ORCPT ); Mon, 11 May 2020 07:58:17 -0400 Received: from localhost (fw-tnat.cambridge.arm.com [217.140.96.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DDFD22075E; Mon, 11 May 2020 11:58:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589198296; bh=I7c/5QR0NUZxXyJ3bfQU4K67hU6vugawyRi1MoWi3Ag=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hMYxExIkbBzpZ8xg1+7zwz1nUpF1p694bpxCsfJ0x+6ZYVxyIZSYhNLWVUmx5cS2U U6vX1F9U22Pn8tffCzSxGDxl96iWaXHHGgGFEDuRfBzRuZP/QWtkoajrB+4xZRf+F8 yoXXlU4MuhX59fX9LOFqETt7nYbJLAk8zxsUReio= Date: Mon, 11 May 2020 12:58:13 +0100 From: Mark Brown To: Serge Semin Cc: Serge Semin , Andy Shevchenko , Vinod Koul , Viresh Kumar , Dan Williams , Alexey Malahov , Thomas Bogendoerfer , Paul Burton , Ralf Baechle , Arnd Bergmann , Rob Herring , linux-mips@vger.kernel.org, devicetree@vger.kernel.org, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 4/6] dmaengine: dw: Print warning if multi-block is unsupported Message-ID: <20200511115813.GG8216@sirena.org.uk> References: <20200306131048.ADBE18030797@mail.baikalelectronics.ru> <20200508105304.14065-1-Sergey.Semin@baikalelectronics.ru> <20200508105304.14065-5-Sergey.Semin@baikalelectronics.ru> <20200508112604.GJ185537@smile.fi.intel.com> <20200508115334.GE4820@sirena.org.uk> <20200511021016.wptcgnc3iq3kadgz@mobilestation> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="fwqqG+mf3f7vyBCB" Content-Disposition: inline In-Reply-To: <20200511021016.wptcgnc3iq3kadgz@mobilestation> X-Cookie: TANSTAAFL User-Agent: Mutt/1.10.1 (2018-07-13) Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org --fwqqG+mf3f7vyBCB Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, May 11, 2020 at 05:10:16AM +0300, Serge Semin wrote: > Alas linearizing the SPI messages won't help in this case because the DW DMA > driver will split it into the max transaction chunks anyway. That sounds like you need to also impose a limit on the maximum message size as well then, with that you should be able to handle messages up to whatever that limit is. There's code for that bit already, so long as the limit is not too low it should be fine for most devices and client drivers can see the limit so they can be updated to work with it if needed. --fwqqG+mf3f7vyBCB Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl65PdUACgkQJNaLcl1U h9CBqgf+PZERckWsOqLfM9GL+SqMyC0673X9Gu0EsD3d7Ew+bDzZXCP8IFVs0dXB kmzF1l+0PHatJ27mV6GPxEAZby+fbbxYZo7/YiDxgE5ortZH58vhYgjFf3gG6XtD SAsfGyowPpK+/2sIGN7pAzXyFMueva4wfHcz3Q74DiSbwc+XugWuS6yHOYsJVrdx 8xhvwaO2S3Wq9G5yJbETpknlzXhGJgTIYF6H86fPOCkqW06c+RiWubK5c2SLj4d6 6CQ/C0vlsL5GOgC8XcOh8EIgZ/XUfPShqn4/U/f3XotpHVmifCJzvsYB77aB7PFx jegHvOJtAGGNPdjuGA5MTUIkYefFYQ== =ko68 -----END PGP SIGNATURE----- --fwqqG+mf3f7vyBCB--