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 B269BC0044D for ; Mon, 16 Mar 2020 12:17:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7F3AB20663 for ; Mon, 16 Mar 2020 12:17:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584361074; bh=fFz5+gvXzmOrpuY8ZHDT9sdLk2O/vOrVVMCc9vpwRqs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=qpyM2CKL9w7ZKWtHMNiyxYEVxP5Ni3rBNaa180s/boPCcFcCt1cbmOk188G5Nq4d4 VdhNYTdzoxZgJveJ2Vs2r63ABEdjpye+iwUUkLqQ8I5ED4spfSA+j9nLN7KeYu+IgH wYZU5KDkRFwBO7QVNd8pprS23J85vnVCfz/y2AsI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730986AbgCPMRx (ORCPT ); Mon, 16 Mar 2020 08:17:53 -0400 Received: from foss.arm.com ([217.140.110.172]:47236 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730969AbgCPMRx (ORCPT ); Mon, 16 Mar 2020 08:17:53 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A74D830E; Mon, 16 Mar 2020 05:17:52 -0700 (PDT) Received: from localhost (unknown [10.37.6.21]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2BB503F52E; Mon, 16 Mar 2020 05:17:52 -0700 (PDT) Date: Mon, 16 Mar 2020 12:17:50 +0000 From: Mark Brown To: =?utf-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= Cc: linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] spi: fix cs_change for last transfer Message-ID: <20200316121750.GD5010@sirena.org.uk> References: <45912ba25c34a63b8098f471c3c8ebf8857a4716.1584292056.git.mirq-linux@rere.qmqm.pl> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="9UV9rz0O2dU/yYYn" Content-Disposition: inline In-Reply-To: <45912ba25c34a63b8098f471c3c8ebf8857a4716.1584292056.git.mirq-linux@rere.qmqm.pl> X-Cookie: I thought YOU silenced the guard! User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --9UV9rz0O2dU/yYYn Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, Mar 15, 2020 at 06:08:53PM +0100, Micha=C5=82 Miros=C5=82aw wrote: > Generic spi_transfer_one_message() implementation introduced in > commit b158935f70b9 has a bug in cs_change handling: it keeps CS > asserted when cs_change is set. Fix it. > struct spi_transfer *xfer; > - bool keep_cs =3D false; > + bool keep_cs =3D true; > int ret =3D 0; > struct spi_statistics *statm =3D &ctlr->statistics; > struct spi_statistics *stats =3D &msg->spi->statistics; > @@ -1268,7 +1268,7 @@ static int spi_transfer_one_message(struct spi_cont= roller *ctlr, > if (xfer->cs_change) { > if (list_is_last(&xfer->transfer_list, > &msg->transfers)) { > - keep_cs =3D true; > + keep_cs =3D false; > } else { This is the opposite of the intended behaviour - we want to deassert chip select at the end of the message unless cs_change is set on the last transfer. If this were broken I would expect to see widespread problems being reported. --9UV9rz0O2dU/yYYn Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl5vbm0ACgkQJNaLcl1U h9BMdQf5AWzcmvns3J9jyWP93QCJquixA0rC5Yq66TDu3Vo6Qrfavnr7xme7k1Wh y6MTSaGKPYH1Y0WzSuQfoFzNOK8dTs9LskJ3D+rZo3hC4IhDKiJQzlEJXK45uLBu 7dQK6bfsI1wSkL6PW89MmfxhrtFV+/EtlocxGVcyy50c1Wo6bGC/U6rak0GUjQhj xD9ig3QyjEBIqvVnv8+FxdE8bjQm2KEhcNOwcKveKKB1YtdYbNeiGw0qY3X6RaFD oNGdZTtvaz5GoT9Wr11qWMWqD/fjecNXwxXWSioAm/UWCO3xN471cO2Ip8TXMZbU Hr2VvQWOFAf5zN6N4XPf3/ZHGhku6A== =1SXT -----END PGP SIGNATURE----- --9UV9rz0O2dU/yYYn--