From patchwork Fri Apr 5 16:05:33 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guenter Roeck X-Patchwork-Id: 10887601 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4D7EB1390 for ; Fri, 5 Apr 2019 16:05:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 377F328AA2 for ; Fri, 5 Apr 2019 16:05:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 299AF28AB6; Fri, 5 Apr 2019 16:05:37 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BD91828AA2 for ; Fri, 5 Apr 2019 16:05:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726730AbfDEQFg (ORCPT ); Fri, 5 Apr 2019 12:05:36 -0400 Received: from mail-pg1-f195.google.com ([209.85.215.195]:34282 "EHLO mail-pg1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726135AbfDEQFg (ORCPT ); Fri, 5 Apr 2019 12:05:36 -0400 Received: by mail-pg1-f195.google.com with SMTP id v12so3317919pgq.1 for ; Fri, 05 Apr 2019 09:05:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id; bh=XYhsYoEDGB+ZEIE1cuPMz0TSx1PXeGfwjhIziFu45CY=; b=pw229hK9j8QGWhl2pRgG7abH/CE4EBtyHpNrXez/ds1PEF2YXBc6Lj8xqI4ImZCcC3 soQ/cQ0QPDhTdmRSirZX6fQ7xxhyVvj7byMF7CZj5jag9YebDNqH6rkoBXMejSYkw6Ub 5hRil5wNXCeY6yrtq0vOV1lrNpDgeYMgEdFaCEL7fTh/X+o0OWCYiNN5P5LPjVsdpcYd tO0HdcmKw/oO2U43hGBayGPBatmWcNrQwN93NKoXzyPre8lhlBys85OwyYCoaideDURZ f2eSkwTaU39QSeaMBie5eonMHMOGCtOBzA8ZBxN0Jt1hT3I+Ei7aQS0GQOcYAhIsmR83 YRoQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id; bh=XYhsYoEDGB+ZEIE1cuPMz0TSx1PXeGfwjhIziFu45CY=; b=M9S8iVDIzPsw2zwTal7D+GujlbbLucBrfJq9nvPTFF2lmJTPXVOr23X/8cRXpLmWH1 QaEuvgpvSwyxt/OKtstuJkQxi7V1/CL5+KJw5fWweClcDjP1hKHJpbMYFQhXHYAb1Frx W/jCYOEGpBnjNEW+x2j++bmqQjZUwtpBtoyyFEiJVPYJaC6FCX+8sEVkYRxdnLvHfsG1 qkXzza8tSC4KsMoVbPk8dP/x0A1PbwGdkfpJbq/qik1sHxwcKIMg5/cenVJWrrSA7lX5 Kk4Li4hhcWAIktpBWoqSGDY4sTV3DwfxsZlW499zghGR0FWUinO4Ct67eKzhP6kLbGcm w63w== X-Gm-Message-State: APjAAAVuVHotqhyK3jYSMVXewYGg+DM3sFsCBZWipkfzR87jTxGYXF54 pr/VbI45bHwjo0sNFWEe+v1bGMuh X-Google-Smtp-Source: APXvYqw+Y2b2TVNfB4Eay9v4dLYL+YrvaaAYdcuF6qTE6qks7dkfM5lXw+PeJ5vvkoyaSiUYp4wUhA== X-Received: by 2002:a63:6fc1:: with SMTP id k184mr12639924pgc.239.1554480335516; Fri, 05 Apr 2019 09:05:35 -0700 (PDT) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id j67sm29949000pfc.72.2019.04.05.09.05.34 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 05 Apr 2019 09:05:35 -0700 (PDT) From: Guenter Roeck To: Hardware Monitoring Cc: Jean Delvare , Guenter Roeck , John Garry Subject: [PATCH v2] hwmon: (smsc47m1) Use request_muxed_region for Super-IO accesses Date: Fri, 5 Apr 2019 09:05:33 -0700 Message-Id: <1554480333-17945-1-git-send-email-linux@roeck-us.net> X-Mailer: git-send-email 2.7.4 Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Super-IO accesses may fail on a system with no or unmapped LPC bus. Also, other drivers may attempt to access the LPC bus at the same time, resulting in undefined behavior. Use request_muxed_region() to ensure that IO access on the requested address space is supported, and to ensure that access by multiple drivers is synchronized. Fixes: 8d5d45fb1468 ("I2C: Move hwmon drivers (2/3)") Reported-by: Kefeng Wang Reported-by: John Garry Cc: John Garry Signed-off-by: Guenter Roeck Acked-by: John Garry --- v2: Fix subject, handle error in smsc47m1_restore() drivers/hwmon/smsc47m1.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) diff --git a/drivers/hwmon/smsc47m1.c b/drivers/hwmon/smsc47m1.c index 5d0c6eaae6f2..5f92eab24c62 100644 --- a/drivers/hwmon/smsc47m1.c +++ b/drivers/hwmon/smsc47m1.c @@ -73,16 +73,21 @@ superio_inb(int reg) /* logical device for fans is 0x0A */ #define superio_select() superio_outb(0x07, 0x0A) -static inline void +static inline int superio_enter(void) { + if (!request_muxed_region(REG, 2, DRVNAME)) + return -EBUSY; + outb(0x55, REG); + return 0; } static inline void superio_exit(void) { outb(0xAA, REG); + release_region(REG, 2); } #define SUPERIO_REG_ACT 0x30 @@ -535,8 +540,12 @@ static int __init smsc47m1_find(struct smsc47m1_sio_data *sio_data) { u8 val; unsigned short addr; + int err; + + err = superio_enter(); + if (err) + return err; - superio_enter(); val = force_id ? force_id : superio_inb(SUPERIO_REG_DEVID); /* @@ -612,13 +621,14 @@ static int __init smsc47m1_find(struct smsc47m1_sio_data *sio_data) static void smsc47m1_restore(const struct smsc47m1_sio_data *sio_data) { if ((sio_data->activate & 0x01) == 0) { - superio_enter(); - superio_select(); - - pr_info("Disabling device\n"); - superio_outb(SUPERIO_REG_ACT, sio_data->activate); - - superio_exit(); + if (!superio_enter()) { + superio_select(); + pr_info("Disabling device\n"); + superio_outb(SUPERIO_REG_ACT, sio_data->activate); + superio_exit(); + } else { + pr_warn("Failed to disable device\n"); + } } }