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=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 67F5DC433E0 for ; Tue, 16 Jun 2020 16:09:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4B8652071A for ; Tue, 16 Jun 2020 16:09:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592323769; bh=VgkC+fRBKLBKgQ0OEx+Emu859oW44liBSJU0qTAPumQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wNV+Ph9dTmvpb//1IuYEj7UUsMvJM/mtGscszLk96l2kF/jlaOIdDtYHDwB+BbqLx 3CdvbvRrCl63g2gPS5Pnw7ctlPV8/mvruyQFXDEKvBaHg1mCM0LOJqI8uEmm0reTfg fSDYsUDQ8WoCgZY9tVIcO6YZRvN+GAqAnvBHhIzU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732530AbgFPQJT (ORCPT ); Tue, 16 Jun 2020 12:09:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:36558 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732067AbgFPPpT (ORCPT ); Tue, 16 Jun 2020 11:45:19 -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 34E112098B; Tue, 16 Jun 2020 15:45:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592322318; bh=VgkC+fRBKLBKgQ0OEx+Emu859oW44liBSJU0qTAPumQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cZF4KBO2tlutyw080GgJ+kvxl/kaHZMLne/cPlCoCcdVk6pSFAj8HhFQoftsBsDlW PyPSj29Qn+K5A4qBUhsnn9a2fGow+s+XKabdPP82BRZEvUBHki+003+yqI3OGVTniB 4/Rks7Q/lsqOxJdBgrxR3n65cPVY8V9+RYS4n0a4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lukas Wunner , Mark Brown Subject: [PATCH 5.7 084/163] spi: bcm2835: Fix controller unregister order Date: Tue, 16 Jun 2020 17:34:18 +0200 Message-Id: <20200616153110.867877823@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200616153106.849127260@linuxfoundation.org> References: <20200616153106.849127260@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 9dd277ff92d06f6aa95b39936ad83981d781f49b upstream. The BCM2835 SPI driver uses devm_spi_register_controller() on bind. As a consequence, on unbind, __device_release_driver() first invokes bcm2835_spi_remove() before unregistering the SPI controller via devres_release_all(). This order is incorrect: bcm2835_spi_remove() tears down the DMA channels and 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_controller() 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_controller(). Note that the struct spi_controller as well as the driver-private data are not freed until after bcm2835_spi_remove() has finished, so accessing them is safe. Fixes: 247263dba208 ("spi: bcm2835: use devm_spi_register_master()") Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v3.13+ Link: https://lore.kernel.org/r/2397dd70cdbe95e0bc4da2b9fca0f31cb94e5aed.1589557526.git.lukas@wunner.de Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spi-bcm2835.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -1347,7 +1347,7 @@ static int bcm2835_spi_probe(struct plat goto out_dma_release; } - err = devm_spi_register_controller(&pdev->dev, ctlr); + err = spi_register_controller(ctlr); if (err) { dev_err(&pdev->dev, "could not register SPI controller: %d\n", err); @@ -1374,6 +1374,8 @@ static int bcm2835_spi_remove(struct pla bcm2835_debugfs_remove(bs); + spi_unregister_controller(ctlr); + /* Clear FIFOs, and disable the HW block */ bcm2835_wr(bs, BCM2835_SPI_CS, BCM2835_SPI_CS_CLEAR_RX | BCM2835_SPI_CS_CLEAR_TX);