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 AAE8CC433E0 for ; Tue, 16 Jun 2020 15:45:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8C0572151B for ; Tue, 16 Jun 2020 15:45:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592322313; bh=wtNPFtGFotQHpz0yNm/HnBPZw/CMNGj4GaPvoRT6xos=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=CcDFLIB4L32f5HQ6m7mHav+naUZI9k0DkTAhaR5ukCNK9Hbav37leM9ID78/BB/HJ nfO+IY7ARjmRIYO2UGmwFxoU3P84zz6gElFMHwg9VhwvATEid2YWi8Ww1IHJ30D94E 8175jxrzpTECCsyBmfaVAwflKJQ/UdGcRA+LjE+I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732059AbgFPPpL (ORCPT ); Tue, 16 Jun 2020 11:45:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:36106 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730829AbgFPPpG (ORCPT ); Tue, 16 Jun 2020 11:45:06 -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 E3E4821531; Tue, 16 Jun 2020 15:45:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592322306; bh=wtNPFtGFotQHpz0yNm/HnBPZw/CMNGj4GaPvoRT6xos=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XwVRWt9W0ejVXkQyED8lCrjDjlJAC5ZevYFsgRJ0jzvqkNcz8n+00WRPXWLyi0GN8 nN8dzAxrnclUctikIrgzUFlQ6U7AFyfewcPxgLFUKh0+J8R8xBZTVU1zk6jGxJZHsT 7yUa8Zvivtkc9uNc2UxYJJhc/FXa6fyyGWPRNAgY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lukas Wunner , Andy Shevchenko , Baruch Siach , Mark Brown Subject: [PATCH 5.7 080/163] spi: dw: Fix controller unregister order Date: Tue, 16 Jun 2020 17:34:14 +0200 Message-Id: <20200616153110.675419172@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 ca8b19d61e3fce5d2d7790cde27a0b57bcb3f341 upstream. The Designware SPI driver uses devm_spi_register_controller() on bind. As a consequence, on unbind, __device_release_driver() first invokes dw_spi_remove_host() before unregistering the SPI controller via devres_release_all(). This order is incorrect: dw_spi_remove_host() shuts down the chip, rendering the SPI bus inaccessible even though the SPI controller is still registered. When the SPI controller is subsequently unregistered, it unbinds all its slave devices. Because their drivers cannot access the SPI bus, e.g. to quiesce interrupts, the slave devices may be left in an improper state. As a rule, devm_spi_register_controller() must not be used if the ->remove() hook performs teardown steps which shall be performed after unregistering the controller and specifically after unbinding of slaves. Fix by reverting to the non-devm variant of spi_register_controller(). An alternative approach would be to use device-managed functions for all steps in dw_spi_remove_host(), e.g. by calling devm_add_action_or_reset() on probe. However that approach would add more LoC to the driver and it wouldn't lend itself as well to backporting to stable. Fixes: 04f421e7b0b1 ("spi: dw: use managed resources") Signed-off-by: Lukas Wunner Reviewed-by: Andy Shevchenko Cc: stable@vger.kernel.org # v3.14+ Cc: Baruch Siach Link: https://lore.kernel.org/r/3fff8cb8ae44a9893840d0688be15bb88c090a14.1590408496.git.lukas@wunner.de Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spi-dw.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/spi/spi-dw.c +++ b/drivers/spi/spi-dw.c @@ -534,7 +534,7 @@ int dw_spi_add_host(struct device *dev, } } - ret = devm_spi_register_controller(dev, master); + ret = spi_register_controller(master); if (ret) { dev_err(&master->dev, "problem registering spi master\n"); goto err_dma_exit; @@ -558,6 +558,8 @@ void dw_spi_remove_host(struct dw_spi *d { dw_spi_debugfs_remove(dws); + spi_unregister_controller(dws->master); + if (dws->dma_ops && dws->dma_ops->dma_exit) dws->dma_ops->dma_exit(dws);