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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,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 AEF42C3A589 for ; Tue, 20 Aug 2019 13:44:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8171122DD6 for ; Tue, 20 Aug 2019 13:44:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566308643; bh=kKQb/INrTFnCBj1QOGr23fLCsE8NmwgEu+JBC7HBdlA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=t2106WhebRNjIKe6S9PxUTRrKfsH+4PZUh7/1CDNBZ/asjYRfJfyJSzF+lcnQub/R ne6Ln6XAnDazNH6kGlDqL4+NmGIAic1sBlEpmVjwMjVd2IaCxmykrRTjcwyljDzItb GJH77wjvzTAWU1ktqTpADML2ZUBwrU9mn6tG9MPI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730919AbfHTNoC (ORCPT ); Tue, 20 Aug 2019 09:44:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:39120 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730846AbfHTNnV (ORCPT ); Tue, 20 Aug 2019 09:43:21 -0400 Received: from sasha-vm.mshome.net (unknown [12.236.144.82]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7C6C022DBF; Tue, 20 Aug 2019 13:43:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566308601; bh=kKQb/INrTFnCBj1QOGr23fLCsE8NmwgEu+JBC7HBdlA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oM5YZZpciKc1PyHwfMEgv223gMEHNB4YUaNahfv2SWb+pvbPGS5ZFRW+cXvfj4qYL 13ZQAoCRp1ygigDI7nEMVFcVg8f1yMcIkvv1Duk8qLuJzSmanVfYrMar/GexflV6yF Lu5D+ggwsECDr3A4HF6VwVA5giOL1joJ57u+Y03o= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Wolfram Sang , Krzysztof Adamski , Wolfram Sang , Sasha Levin , linux-i2c@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 5/7] i2c: emev2: avoid race when unregistering slave client Date: Tue, 20 Aug 2019 09:43:13 -0400 Message-Id: <20190820134315.11720-5-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190820134315.11720-1-sashal@kernel.org> References: <20190820134315.11720-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Wolfram Sang [ Upstream commit d7437fc0d8291181debe032671a289b6bd93f46f ] After we disabled interrupts, there might still be an active one running. Sync before clearing the pointer to the slave device. Fixes: c31d0a00021d ("i2c: emev2: add slave support") Reported-by: Krzysztof Adamski Signed-off-by: Wolfram Sang Reviewed-by: Krzysztof Adamski Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/busses/i2c-emev2.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-emev2.c b/drivers/i2c/busses/i2c-emev2.c index 96bb4e7490128..0218ba6eb26ab 100644 --- a/drivers/i2c/busses/i2c-emev2.c +++ b/drivers/i2c/busses/i2c-emev2.c @@ -72,6 +72,7 @@ struct em_i2c_device { struct completion msg_done; struct clk *sclk; struct i2c_client *slave; + int irq; }; static inline void em_clear_set_bit(struct em_i2c_device *priv, u8 clear, u8 set, u8 reg) @@ -342,6 +343,12 @@ static int em_i2c_unreg_slave(struct i2c_client *slave) writeb(0, priv->base + I2C_OFS_SVA0); + /* + * Wait for interrupt to finish. New slave irqs cannot happen because we + * cleared the slave address and, thus, only extension codes will be + * detected which do not use the slave ptr. + */ + synchronize_irq(priv->irq); priv->slave = NULL; return 0; @@ -358,7 +365,7 @@ static int em_i2c_probe(struct platform_device *pdev) { struct em_i2c_device *priv; struct resource *r; - int irq, ret; + int ret; priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) @@ -391,8 +398,8 @@ static int em_i2c_probe(struct platform_device *pdev) em_i2c_reset(&priv->adap); - irq = platform_get_irq(pdev, 0); - ret = devm_request_irq(&pdev->dev, irq, em_i2c_irq_handler, 0, + priv->irq = platform_get_irq(pdev, 0); + ret = devm_request_irq(&pdev->dev, priv->irq, em_i2c_irq_handler, 0, "em_i2c", priv); if (ret) goto err_clk; @@ -402,7 +409,8 @@ static int em_i2c_probe(struct platform_device *pdev) if (ret) goto err_clk; - dev_info(&pdev->dev, "Added i2c controller %d, irq %d\n", priv->adap.nr, irq); + dev_info(&pdev->dev, "Added i2c controller %d, irq %d\n", priv->adap.nr, + priv->irq); return 0; -- 2.20.1