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=-3.6 required=3.0 tests=BAYES_00,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 70323C2D0A3 for ; Mon, 9 Nov 2020 14:24:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B97720674 for ; Mon, 9 Nov 2020 14:24:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="jevuavzx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730197AbgKIOYW (ORCPT ); Mon, 9 Nov 2020 09:24:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34012 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730035AbgKIOYW (ORCPT ); Mon, 9 Nov 2020 09:24:22 -0500 Received: from mail-pg1-x541.google.com (mail-pg1-x541.google.com [IPv6:2607:f8b0:4864:20::541]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5647BC0613CF; Mon, 9 Nov 2020 06:24:22 -0800 (PST) Received: by mail-pg1-x541.google.com with SMTP id r186so7296852pgr.0; Mon, 09 Nov 2020 06:24:22 -0800 (PST) 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=I0JWH1SE4fNuIvP9pni+ltgPPpUk5UXe6Ja6Dl7UHNM=; b=jevuavzxcW3HQorjQwheDNNI2A/fFPMvKDn0mcJGqAZBwBmCKwMTdKJpXVkQPCC+xc 0wzcYAZ5Q9lDDiVmS1vQywVJM7xxtr6bERgHvaw2TEYngDMWsfm/UvAbGMQVmFwZV6AE lsMhtSpPyA8oDLU44HCn1M8NMYKKMjwqaHtlsW2DLk/QnsFFxCiUlGtC6gh6DgouC3yv ZuWZI00QluQK5J/HrBKfORylQVbU6tR9TYZ61UkFhd1dTptjTzMHdN3pV6bzUplif+Sy B0mjgvK9zvjtFqHsvXmc3piUc2zpJLAweR5Z9rqfcxL7qRHQeczNP/gpziee4ovyEAeC SdMA== 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=I0JWH1SE4fNuIvP9pni+ltgPPpUk5UXe6Ja6Dl7UHNM=; b=HmhhnF8mLX8j7KnSWena5LS4wePUGslk2xCmf8mrR4XxvwYe3hCd4UeDIuPlOR0E7w yuBdI01C1WRWTlTsvjoHngUU+G4XZHY2lZ8W0ivja1L/xLpC00sXYTe/drf1GJ99yf7Q Is0FWJwtrUg2HOALoHX/82FF30aPPEomlm+zZVv5M6iCLk25iq/PFdpoM/AwJa34LNWc j4MeWH/SERu4BdsoAsFfbm5rBuUkYSJSE+ypH4tgo7oDgR4xRURaDUz3KOSUNUJaXA/r UsKWQ/i+zzf03Z1dSzI33t5sVG90OTdsR71L3hiCKUgPmdyeCUEmVfr5ixttSycMvPIa ObZg== X-Gm-Message-State: AOAM530vNtA7ozUJYR6RKN91xGbSbD6ntA9HYPDVG3yXD+kNAqg6MjdH 1UTxGHPXkH4rMh4BGTtp7Of1IJrrQK8470JmPoM= X-Google-Smtp-Source: ABdhPJwidLp7E0/LPaDZe10ybjQfbINm9x2SALC+02oxtUeVB16O5+WJcb4yxzJw4LIARuGK1yf21/HmLLMPqjNbLWw= X-Received: by 2002:a63:4511:: with SMTP id s17mr13018417pga.4.1604931861810; Mon, 09 Nov 2020 06:24:21 -0800 (PST) MIME-Version: 1.0 References: <20201106150706.29089-1-TheSven73@gmail.com> In-Reply-To: <20201106150706.29089-1-TheSven73@gmail.com> From: Andy Shevchenko Date: Mon, 9 Nov 2020 16:25:10 +0200 Message-ID: Subject: Re: [PATCH v1] spi: fix client driver breakages when using GPIO descriptors To: Sven Van Asbroeck Cc: Mark Brown , Linus Walleij , Jonathan Cameron , Simon Han , Lukas Wunner , linux-spi , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org On Fri, Nov 6, 2020 at 5:08 PM Sven Van Asbroeck wrote: > > From: Sven Van Asbroeck > > Commit f3186dd87669 ("spi: Optionally use GPIO descriptors for CS GPIOs") > introduced the optional use of GPIO descriptors for chip selects. > > A side-effect of this change: when a SPI bus uses GPIO descriptors, > all its client devices have SPI_CS_HIGH set in spi->mode. This flag is > required for the SPI bus to operate correctly. > > This unfortunately breaks many client drivers, which use the following > pattern to configure their underlying SPI bus: > > static int client_device_probe(struct spi_device *spi) > { > ... > spi->mode = SPI_MODE_0; > spi->bits_per_word = 8; > err = spi_setup(spi); > .. > } > > In short, many client drivers overwrite the SPI_CS_HIGH bit in > spi->mode, and break the underlying SPI bus driver. Sounds like "many SPI drivers have to be fixed". -- With Best Regards, Andy Shevchenko