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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 D22D6C43462 for ; Wed, 12 May 2021 14:59:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E87D61453 for ; Wed, 12 May 2021 14:59:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232517AbhELPAX (ORCPT ); Wed, 12 May 2021 11:00:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:46196 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231453AbhELO6M (ORCPT ); Wed, 12 May 2021 10:58:12 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A16326143C; Wed, 12 May 2021 14:55:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1620831359; bh=V+zRJns6/Pnp7to6Ws9ps4uD32QHQZQr80zkSJFlhcM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uTd5kMTIhtU/nhITebhCScGkovfW2sdr7k2fzp0IJcp8Usg93uhLPPokQaQUggTUI Fe4Qfo14u3aaLFqDV/MYG50zIMMjywv3F+cKCKZqztX02UgdZxiraZ4wYW1HGDbigD TYvsUT7K7Of9L7SGgOp0SXkINBjyGw/mZvk8yAHw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Antonio Borneo , Alain Volmat , Mark Brown , Sasha Levin Subject: [PATCH 5.4 081/244] spi: stm32: drop devres version of spi_register_master Date: Wed, 12 May 2021 16:47:32 +0200 Message-Id: <20210512144745.624780437@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210512144743.039977287@linuxfoundation.org> References: <20210512144743.039977287@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Antonio Borneo [ Upstream commit 8d559a64f00b59af9cc02b803ff52f6e6880a651 ] A call to spi_unregister_master() triggers calling remove() for all the spi devices binded to the spi master. Some spi device driver requires to "talk" with the spi device during the remove(), e.g.: - a LCD panel like drivers/gpu/drm/panel/panel-lg-lg4573.c will turn off the backlighting sending a command over spi. This implies that the spi master must be fully functional when spi_unregister_master() is called, either if it is called explicitly in the master's remove() code or implicitly by the devres framework. Devres calls devres_release_all() to release all the resources "after" the remove() of the spi master driver (check code of __device_release_driver() in drivers/base/dd.c). If the spi master driver has an empty remove() then there would be no issue; the devres_release_all() will release everything in reverse order w.r.t. probe(). But if code in spi master driver remove() disables the spi or makes it not functional (like in this spi-stm32), then devres cannot be used safely for unregistering the spi master and the binded spi devices. Replace devm_spi_register_master() with spi_register_master() and add spi_unregister_master() as first action in remove(). Fixes: dcbe0d84dfa5 ("spi: add driver for STM32 SPI controller") Signed-off-by: Antonio Borneo Signed-off-by: Alain Volmat Link: https://lore.kernel.org/r/1615545286-5395-1-git-send-email-alain.volmat@foss.st.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi-stm32.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c index 9e7a6de3c43d..3af6a5a3a4b2 100644 --- a/drivers/spi/spi-stm32.c +++ b/drivers/spi/spi-stm32.c @@ -1926,7 +1926,7 @@ static int stm32_spi_probe(struct platform_device *pdev) pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); - ret = devm_spi_register_master(&pdev->dev, master); + ret = spi_register_master(master); if (ret) { dev_err(&pdev->dev, "spi master registration failed: %d\n", ret); @@ -1980,6 +1980,7 @@ static int stm32_spi_remove(struct platform_device *pdev) struct spi_master *master = platform_get_drvdata(pdev); struct stm32_spi *spi = spi_master_get_devdata(master); + spi_unregister_master(master); spi->cfg->disable(spi); if (master->dma_tx) -- 2.30.2