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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 B4504C433E0 for ; Fri, 19 Jun 2020 14:36:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9425121548 for ; Fri, 19 Jun 2020 14:36:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592577379; bh=TJ37aGeRnF5SOqXAIKJ5XavM4oJ4fEAX1NdGoYH1k6g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=iF0CvIjWm1ckoSecTpP9u9g0Mkx31SVp0jYV1zX+eJOtlyLROZ/qY+JMU5P/setbj 1Tof11zcIK29+eywLkJ9USk7K9HwRX2bIDNdVsguH3qNeOyUE3er2klDw41iQ2lbv5 EzYgbMmSj66Vk5AWcIimMTKzYxmBxN+Rkfoyhrl0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387484AbgFSOgP (ORCPT ); Fri, 19 Jun 2020 10:36:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:52376 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387446AbgFSOgC (ORCPT ); Fri, 19 Jun 2020 10:36:02 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 C1DB921548; Fri, 19 Jun 2020 14:36:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592577362; bh=TJ37aGeRnF5SOqXAIKJ5XavM4oJ4fEAX1NdGoYH1k6g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Ffv+Xthkpr9+nrxoI7cQQIxcNIKulXWz6qpi+Td970EMJtxTFCq07lQ7Tj/fEOtTc XANjTGCmUNRgFaidHyWDNmKiNm5P9oKR6mSMLagfVYQmA4OwMEiNY4oxfrXfSc7nEm mWNQOaxJFKs0BEn/OzKyHIOeDHOYJ5PlYoctwtJA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lukas Wunner , Martin Sperl , Mark Brown Subject: [PATCH 4.4 020/101] spi: bcm2835aux: Fix controller unregister order Date: Fri, 19 Jun 2020 16:32:09 +0200 Message-Id: <20200619141615.143856517@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200619141614.001544111@linuxfoundation.org> References: <20200619141614.001544111@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lukas Wunner commit b9dd3f6d417258ad0beeb292a1bc74200149f15d upstream. The BCM2835aux SPI driver uses devm_spi_register_master() on bind. As a consequence, on unbind, __device_release_driver() first invokes bcm2835aux_spi_remove() before unregistering the SPI controller via devres_release_all(). This order is incorrect: bcm2835aux_spi_remove() turns off the SPI controller, including its interrupts and clock. The SPI controller is thus no longer usable. When the SPI controller is subsequently unregistered, it unbinds all its slave devices. If their drivers need to access the SPI bus, e.g. to quiesce their interrupts, unbinding will fail. As a rule, devm_spi_register_master() must not be used if the ->remove() hook performs teardown steps which shall be performed after unbinding of slaves. Fix by using the non-devm variant spi_register_master(). Note that the struct spi_master as well as the driver-private data are not freed until after bcm2835aux_spi_remove() has finished, so accessing them is safe. Fixes: 1ea29b39f4c8 ("spi: bcm2835aux: add bcm2835 auxiliary spi device driver") Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v4.4+ Cc: Martin Sperl Link: https://lore.kernel.org/r/32f27f4d8242e4d75f9a53f7e8f1f77483b08669.1589557526.git.lukas@wunner.de Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spi-bcm2835aux.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/spi/spi-bcm2835aux.c +++ b/drivers/spi/spi-bcm2835aux.c @@ -457,7 +457,7 @@ static int bcm2835aux_spi_probe(struct p goto out_clk_disable; } - err = devm_spi_register_master(&pdev->dev, master); + err = spi_register_master(master); if (err) { dev_err(&pdev->dev, "could not register SPI master: %d\n", err); goto out_clk_disable; @@ -477,6 +477,8 @@ static int bcm2835aux_spi_remove(struct struct spi_master *master = platform_get_drvdata(pdev); struct bcm2835aux_spi *bs = spi_master_get_devdata(master); + spi_unregister_master(master); + bcm2835aux_spi_reset_hw(bs); /* disable the HW block by releasing the clock */