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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 2C196C433E9 for ; Fri, 15 Jan 2021 12:57:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F276D2256F for ; Fri, 15 Jan 2021 12:57:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387669AbhAOM5e (ORCPT ); Fri, 15 Jan 2021 07:57:34 -0500 Received: from mail.kernel.org ([198.145.29.99]:41144 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387456AbhAOMeP (ORCPT ); Fri, 15 Jan 2021 07:34:15 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id C0C992336F; Fri, 15 Jan 2021 12:33:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1610714015; bh=YCuT/meOWi39fL2ZvWvY68jiEeri71aX+oqCkmAL4ec=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mP1C+16JZ2/3LTtcQci6mG2CpAAFudOQtiSB0rcbnFcbQLjojzuPfNnRgaas1sXy1 YvhjTVg0L9Icu2RdtHtzPsP9YW55udvi23Z6+KjCiR4KH+R0omM8Kz9RASgyfteWI6 sR5F58uiHdDsrdFFHOAChF3FaY4yk47VQaAslAbk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Linhua Xu , Chunyan Zhang , Wolfram Sang Subject: [PATCH 4.19 25/43] i2c: sprd: use a specific timeout to avoid system hang up issue Date: Fri, 15 Jan 2021 13:27:55 +0100 Message-Id: <20210115121958.272354531@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210115121957.037407908@linuxfoundation.org> References: <20210115121957.037407908@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: Chunyan Zhang commit 0b884fe71f9ee6a5df35e677154256ea2099ebb8 upstream. If the i2c device SCL bus being pulled up due to some exception before message transfer done, the system cannot receive the completing interrupt signal any more, it would not exit waiting loop until MAX_SCHEDULE_TIMEOUT jiffies eclipse, that would make the system seemed hang up. To avoid that happen, this patch adds a specific timeout for message transfer. Fixes: 8b9ec0719834 ("i2c: Add Spreadtrum I2C controller driver") Signed-off-by: Linhua Xu Signed-off-by: Chunyan Zhang [wsa: changed errno to ETIMEDOUT] Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/busses/i2c-sprd.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/drivers/i2c/busses/i2c-sprd.c +++ b/drivers/i2c/busses/i2c-sprd.c @@ -71,6 +71,8 @@ /* timeout (ms) for pm runtime autosuspend */ #define SPRD_I2C_PM_TIMEOUT 1000 +/* timeout (ms) for transfer message */ +#define I2C_XFER_TIMEOUT 1000 /* SPRD i2c data structure */ struct sprd_i2c { @@ -244,6 +246,7 @@ static int sprd_i2c_handle_msg(struct i2 struct i2c_msg *msg, bool is_last_msg) { struct sprd_i2c *i2c_dev = i2c_adap->algo_data; + unsigned long time_left; i2c_dev->msg = msg; i2c_dev->buf = msg->buf; @@ -273,7 +276,10 @@ static int sprd_i2c_handle_msg(struct i2 sprd_i2c_opt_start(i2c_dev); - wait_for_completion(&i2c_dev->complete); + time_left = wait_for_completion_timeout(&i2c_dev->complete, + msecs_to_jiffies(I2C_XFER_TIMEOUT)); + if (!time_left) + return -ETIMEDOUT; return i2c_dev->err; }