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=-2.6 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 A193FCA9EAF for ; Thu, 24 Oct 2019 11:13:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 72ADD20856 for ; Thu, 24 Oct 2019 11:13:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1571915584; bh=cSU5obqMXG3dooXXAZJBScJEXU+miSgZT9YvgohCXkc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=JLEft1dVY+pshz3qX4WTIGvL9tSVn3YUU5tngwSt/aT+a9Mo9qG4Y8mn6BWBO8WqQ fKXFZKAsEJI1ydfNsXiMvFaSIZozxuczSs0u0Tg8fEBSltdBCtz128nHzWgAu0I8sz bIQiaX6HBf9afye+ptRlIUf6u9CetWWVjXn5pPns= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2408030AbfJXLND (ORCPT ); Thu, 24 Oct 2019 07:13:03 -0400 Received: from heliosphere.sirena.org.uk ([172.104.155.198]:34604 "EHLO heliosphere.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405717AbfJXLND (ORCPT ); Thu, 24 Oct 2019 07:13:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sirena.org.uk; s=20170815-heliosphere; h=In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=kxBq9eU5c+pynz4hCMtujUwkOF15d6QuZ5BX1XsZdfc=; b=PB1Zs1NjpAPp1u4Uw9oxpfc+Q vvZOTeMbkchUlC34r6Wa2/Q/Nov/zAlEKPV30ubvgiKmEMp8fwxNi5OjV1MFsZaBAaoNZZmupRVsJ qmoLMCwmELB3UhabdPU4NZY8m6lCQkqW6AutFu2y8XUOMoWYUbc81Kw9s7CbwEoCyruDg=; Received: from cpc102320-sgyl38-2-0-cust46.18-2.cable.virginm.net ([82.37.168.47] helo=ypsilon.sirena.org.uk) by heliosphere.sirena.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1iNb37-0003NI-3z; Thu, 24 Oct 2019 11:13:01 +0000 Received: by ypsilon.sirena.org.uk (Postfix, from userid 1000) id 47323274293C; Thu, 24 Oct 2019 12:13:00 +0100 (BST) Date: Thu, 24 Oct 2019 12:13:00 +0100 From: Mark Brown To: Alvaro Gamez Machado Cc: Michal Simek , Shubhrajyoti Datta , linux-spi@vger.kernel.org, Rob Herring , devicetree@vger.kernel.org Subject: Re: [PATCH] spi: set bits_per_word based on controller's bits_per_word_mask Message-ID: <20191024111300.GD5207@sirena.co.uk> References: <20191024110757.25820-1-alvaro.gamez@hazent.com> <20191024110757.25820-4-alvaro.gamez@hazent.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="EP0wieDxd4TSJjHq" Content-Disposition: inline In-Reply-To: <20191024110757.25820-4-alvaro.gamez@hazent.com> X-Cookie: What foods these morsels be! User-Agent: Mutt/1.10.1 (2018-07-13) Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org --EP0wieDxd4TSJjHq Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Oct 24, 2019 at 01:07:57PM +0200, Alvaro Gamez Machado wrote: > By leaving this value unset, a default value of 8 was being set later on. >=20 > If it happens that the SPI master driver doesn't support this value of 8, > there will be an initial inconsistency between the SPI master and the dev= ice > itself. This isn't a problem for most devices because kernel drivers This will break things, client devices are working on the basis that the default transfer width is 8 bits. As I've repeatedly said if we have different parts of the system with different ideas about the word size we're going to end up with data corruption. Please take this feedback on board. --EP0wieDxd4TSJjHq Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl2xhzsACgkQJNaLcl1U h9BNewf/SgKCEZWVH1yrKLieF/GMxsUxwqzetiY3EiQutLFXjok2pyjmP03nMA7s 0a554YBya1i29mV7kV9HI9dGOJztW0tj4pZaZB3eJQw3DQTPixdBt4sfLLBE2wdW RjAy4kAb9A/5iro7cIpVUqa0eYc5yH5y6hs8gXQv3aI8OU8WDB3r6spYSAvbl0Ey s4ea8XRLT6fk48ul+LESLJdOWShvM/q0SIyUg7IOBk/219pPlcBWnXrA1ttsWrB5 SYoTdtfcCocwvInv3vECNOPe9786EBAsdyQXA7ucvrdRqdifHA2UCGXaHwj/iwC1 7mq2rqHGU7ok+mtgLy/ZhpOzjGPPHg== =uBZS -----END PGP SIGNATURE----- --EP0wieDxd4TSJjHq--