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=-15.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 D02FEC43460 for ; Fri, 30 Apr 2021 01:23:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 87E69613CA for ; Fri, 30 Apr 2021 01:23:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229795AbhD3BYQ (ORCPT ); Thu, 29 Apr 2021 21:24:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229519AbhD3BYP (ORCPT ); Thu, 29 Apr 2021 21:24:15 -0400 Received: from mail-oi1-x236.google.com (mail-oi1-x236.google.com [IPv6:2607:f8b0:4864:20::236]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9F94FC06138B; Thu, 29 Apr 2021 18:23:26 -0700 (PDT) Received: by mail-oi1-x236.google.com with SMTP id t24so11061308oic.10; Thu, 29 Apr 2021 18:23:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=1SYSV1ST5CmyKauB1cfHt/lTjzM1JtgTjndM7qycV2o=; b=Y1xm6h0jsXhEjU0x8/UPm/ebG9B1+44LoKVQV9r5rnnas+5rYWJObWCn8SZo6tSMZ1 cGtznuA8KXtzD+a3KJgBiRpw5l3cTwIHQUxNZT8zUqp07Rhx4BMZFAn8vMSLJSirEz6c fiv0HTIG8Th+seaIerFKPHoWMlf7O6xyzsrT6nZdccuUgfexudsLEMyCbX8t1aF8TiDg +1qJcvWbSL45Ld3V/7iTZvnJS6dmb35psqoGcvGT1hfIWKayXTipB1/SvfAx6c04P9wN 1KH3PflvzzZ+ZjbpJEncNHyBCDeM3jwz9pYUfaTJwWh7sqGe2Wz+Qlw2G3mJ0YMWevob 106g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=1SYSV1ST5CmyKauB1cfHt/lTjzM1JtgTjndM7qycV2o=; b=VrBOG3eojB9s5R83OahWGvBceVlV+lCtjAm43I7yV/3+7+7tBNkO/+pePzjNgmThfg nR8gbJcqjaSwvNWjKVL07lctio9bu+HeI/jdvCDCkkamsyQZw8AyccyAgm6vQtN0IuCc 1I59BT2cVoXEcaxn28uDeh6ayz0px/7j3KmA6N9yEaSjRYYUR1no+l9IzRqhXsz+4Uey eBIcEzizoZ5yeYxecIn6DHveFJXvx4kIEla/fEbALI1PWu9Ph+SKkOVIOWS3TTVCiunS dgkx+/kca2mhPI3WCaqXLYsOkQTFjm4D6E/phOiN4GExAJHdoNOV2b7BWvo6HsIbhDiA jxYw== X-Gm-Message-State: AOAM530TBwjTMJbt6DN+mU3fnhuftslcmYA/1w5r0RjBfl9TgVIa1rzT X0y+tzfs3Jddk8ogag3KdcOrmg+h4lQ= X-Google-Smtp-Source: ABdhPJzhRt2piz5wYQRbzUjle3i0pXTPwyn8+KVGHk8JUisg/wusbUU9Dm6Mk1x9240e2ds0mb6WGg== X-Received: by 2002:a05:6808:2d0:: with SMTP id a16mr2127647oid.116.1619745805896; Thu, 29 Apr 2021 18:23:25 -0700 (PDT) Received: from localhost (108-223-40-66.lightspeed.sntcca.sbcglobal.net. [108.223.40.66]) by smtp.gmail.com with ESMTPSA id k16sm397760ooa.36.2021.04.29.18.23.24 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Thu, 29 Apr 2021 18:23:25 -0700 (PDT) Sender: Guenter Roeck Date: Thu, 29 Apr 2021 18:23:23 -0700 From: Guenter Roeck To: Eddie James Cc: linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, jdelvare@suse.com Subject: Re: [PATCH] hwmon: (occ) Fix poll rate limiting Message-ID: <20210430012323.GA186319@roeck-us.net> References: <20210429151336.18980-1-eajames@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210429151336.18980-1-eajames@linux.ibm.com> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 29, 2021 at 10:13:36AM -0500, Eddie James wrote: > The poll rate limiter time was initialized at zero. This breaks the > comparison in time_after if jiffies is large. Switch to storing the > next update time rather than the previous time, and initialize the > time when the device is probed. > > Fixes: c10e753d43eb ("hwmon (occ): Add sensor types and versions") > Signed-off-by: Eddie James Applied. Thanks, Guenter > --- > drivers/hwmon/occ/common.c | 5 +++-- > drivers/hwmon/occ/common.h | 2 +- > 2 files changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/hwmon/occ/common.c b/drivers/hwmon/occ/common.c > index f1ac153d0b56..967532afb1c0 100644 > --- a/drivers/hwmon/occ/common.c > +++ b/drivers/hwmon/occ/common.c > @@ -217,9 +217,9 @@ int occ_update_response(struct occ *occ) > return rc; > > /* limit the maximum rate of polling the OCC */ > - if (time_after(jiffies, occ->last_update + OCC_UPDATE_FREQUENCY)) { > + if (time_after(jiffies, occ->next_update)) { > rc = occ_poll(occ); > - occ->last_update = jiffies; > + occ->next_update = jiffies + OCC_UPDATE_FREQUENCY; > } else { > rc = occ->last_error; > } > @@ -1165,6 +1165,7 @@ int occ_setup(struct occ *occ, const char *name) > return rc; > } > > + occ->next_update = jiffies + OCC_UPDATE_FREQUENCY; > occ_parse_poll_response(occ); > > rc = occ_setup_sensor_attrs(occ); > diff --git a/drivers/hwmon/occ/common.h b/drivers/hwmon/occ/common.h > index 67e6968b8978..e6df719770e8 100644 > --- a/drivers/hwmon/occ/common.h > +++ b/drivers/hwmon/occ/common.h > @@ -99,7 +99,7 @@ struct occ { > u8 poll_cmd_data; /* to perform OCC poll command */ > int (*send_cmd)(struct occ *occ, u8 *cmd); > > - unsigned long last_update; > + unsigned long next_update; > struct mutex lock; /* lock OCC access */ > > struct device *hwmon;