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=-3.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 D3B21C4321D for ; Thu, 23 Aug 2018 09:11:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 90A1C208C2 for ; Thu, 23 Aug 2018 09:11:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 90A1C208C2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389192AbeHWMkG (ORCPT ); Thu, 23 Aug 2018 08:40:06 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:56970 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727875AbeHWMkG (ORCPT ); Thu, 23 Aug 2018 08:40:06 -0400 Received: from localhost (5355525A.cm-6-6b.dynamic.ziggo.nl [83.85.82.90]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 2F1AC93C; Thu, 23 Aug 2018 09:11:20 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Hans de Goede , Mika Westerberg , Wolfram Sang Subject: [PATCH 4.18 20/22] i2c: core: ACPI: Properly set status byte to 0 for multi-byte writes Date: Thu, 23 Aug 2018 09:56:46 +0200 Message-Id: <20180823074800.444283304@linuxfoundation.org> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180823074759.234685844@linuxfoundation.org> References: <20180823074759.234685844@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hans de Goede commit c463a158cb6c5d9a85b7d894cd4f8116e8bd6be0 upstream. acpi_gsb_i2c_write_bytes() returns i2c_transfer()'s return value, which is the number of transfers executed on success, so 1. The ACPI code expects us to store 0 in gsb->status for success, not 1. Specifically this breaks the following code in the Thinkpad 8 DSDT: ECWR = I2CW = ECWR /* \_SB_.I2C1.BAT0.ECWR */ If ((ECST == Zero)) { ECRD = I2CR /* \_SB_.I2C1.I2CR */ } Before this commit we set ECST to 1, causing the read to never happen breaking battery monitoring on the Thinkpad 8. This commit makes acpi_gsb_i2c_write_bytes() return 0 when i2c_transfer() returns 1, so the single write transfer completed successfully, and makes it return -EIO on for other (unexpected) return values >= 0. Cc: stable@vger.kernel.org Signed-off-by: Hans de Goede Acked-by: Mika Westerberg Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/i2c-core-acpi.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/drivers/i2c/i2c-core-acpi.c +++ b/drivers/i2c/i2c-core-acpi.c @@ -482,11 +482,16 @@ static int acpi_gsb_i2c_write_bytes(stru msgs[0].buf = buffer; ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); - if (ret < 0) - dev_err(&client->adapter->dev, "i2c write failed\n"); kfree(buffer); - return ret; + + if (ret < 0) { + dev_err(&client->adapter->dev, "i2c write failed: %d\n", ret); + return ret; + } + + /* 1 transfer must have completed successfully */ + return (ret == 1) ? 0 : -EIO; } static acpi_status