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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 84BF2C2D0DB for ; Tue, 28 Jan 2020 19:13:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 583E62173E for ; Tue, 28 Jan 2020 19:13:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Q/F/VGHs" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726439AbgA1TNK (ORCPT ); Tue, 28 Jan 2020 14:13:10 -0500 Received: from mail-yw1-f67.google.com ([209.85.161.67]:40839 "EHLO mail-yw1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726002AbgA1TNJ (ORCPT ); Tue, 28 Jan 2020 14:13:09 -0500 Received: by mail-yw1-f67.google.com with SMTP id i126so7057651ywe.7; Tue, 28 Jan 2020 11:13:09 -0800 (PST) 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=8wKVDbM8dSna8Ek2WmGu0py3hsOW6aws0CcQ8clzPl0=; b=Q/F/VGHs771LlF1sjpTuRXeCsaknt7LaVzk9pUl2TOuBLJKDMJjHKjv+kuemKIB4Is EnNcCLglXHnJq/BfgID3gmBwQECKvqDtuMWSx6gounOTn7i/dvNewI1n0UXoeEblKkZb MxWyBHs52ZcrpWAcYodUux65b0Vo5J6N9bOpgsZOfSg4Qwp4p4M83iNvC5R63iMxjQCK pZUiI8Yja10ywMtKlCnw/Q3HU7ViguP3DkZnQGSwwtWUePT8sA5I3Fpeo6UJ6oUYAIVt GqQ+QXszEh/kuz/FXkWoCY53rkL4IJhNwairL+Tji8xHQoZ221t2GWlUXCUcQyAZsNGG PFWg== 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=8wKVDbM8dSna8Ek2WmGu0py3hsOW6aws0CcQ8clzPl0=; b=RUhMSBlJmp8d6Iku5Rsq3zlBQiLenfNGMl0TuVuRumAad/G+q45fYScE2LjcZdkZmM s0Debtk30bBdJuoCIXUhIecZPWjRbQkh5uE8U6nYLfhzxzvBSO/Kb70f98O9rn/VrAll R6qPEe1qFjGO9YCP4kOp5poaD4J/Za9Wq+Bxj87Yt58YgZjfinAM2k3c8mhqCWFngSyp +v2AxhM7eekxxy1inCpu4jQFY4+RemivS8znho1Dw7zj/05xyOZmG0r6nx0q0GneHH87 QKHxVgXI/ZSUTvtseVETt69fT5fgccbWMB5113TnU1zaVA7DPSnDQM/duTu1zlG7FtfB tmGA== X-Gm-Message-State: APjAAAXhA5O953bf+mNvvvupXUoUWn0VUswaqt67jlZNfgLShzx8TswN 9b8FOYyOSLW8yoCZiT8OgRs= X-Google-Smtp-Source: APXvYqza0X/mYL4koOr7/goYIqRMeCTiHeRZYJxKgArDvNT+gdKCvpmjm3KyIxsxUHv0uaUooVE3hQ== X-Received: by 2002:a81:3d42:: with SMTP id k63mr16490295ywa.366.1580238788668; Tue, 28 Jan 2020 11:13:08 -0800 (PST) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id g65sm8473961ywd.109.2020.01.28.11.13.07 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 28 Jan 2020 11:13:08 -0800 (PST) Date: Tue, 28 Jan 2020 11:13:06 -0800 From: Guenter Roeck To: Mike Jones Cc: linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, jdelvare@suse.com, robh+dt@kernel.org, corbet@lwn.net Subject: Re: [PATCH 2/3] hwmon: (pmbus/ltc2978): Fix PMBus polling of MFR_COMMON definitions. Message-ID: <20200128191306.GA32672@roeck-us.net> References: <1580234400-2829-1-git-send-email-michael-a1.jones@analog.com> <1580234400-2829-2-git-send-email-michael-a1.jones@analog.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1580234400-2829-2-git-send-email-michael-a1.jones@analog.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org On Tue, Jan 28, 2020 at 10:59:59AM -0700, Mike Jones wrote: > Change 21537dc driver PMBus polling of MFR_COMMON from bits 5/4 to > bits 6/5. This fixs a LTC297X family bug where polling always returns > not busy even when the part is busy. This fixes a LTC388X and > LTM467X bug where polling used PEND and NOT_IN_TRANS, and BUSY was > not polled, which can lead to NACKing of commands. LTC388X and > LTM467X modules now poll BUSY and PEND, increasing reliability by > eliminating NACKing of commands. > > Signed-off-by: Mike Jones Fixes: e04d1ce9bbb49 ("hwmon: (ltc2978) Add polling for chips requiring it") > --- > drivers/hwmon/pmbus/ltc2978.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwmon/pmbus/ltc2978.c b/drivers/hwmon/pmbus/ltc2978.c > index f01f488..a91ed01 100644 > --- a/drivers/hwmon/pmbus/ltc2978.c > +++ b/drivers/hwmon/pmbus/ltc2978.c > @@ -82,8 +82,8 @@ enum chips { ltc2974, ltc2975, ltc2977, ltc2978, ltc2980, ltc3880, ltc3882, > > #define LTC_POLL_TIMEOUT 100 /* in milli-seconds */ > > -#define LTC_NOT_BUSY BIT(5) > -#define LTC_NOT_PENDING BIT(4) > +#define LTC_NOT_BUSY BIT(6) > +#define LTC_NOT_PENDING BIT(5) > In ltc_wait_ready(), we have: /* * LTC3883 does not support LTC_NOT_PENDING, even though * the datasheet claims that it does. */ mask = LTC_NOT_BUSY; if (data->id != ltc3883) mask |= LTC_NOT_PENDING; The semantics of this code is now different: It means that on LTC3883 only bit 6 is checked; previously, it was bit 5. I agree that the above change makes sense, but it doesn't seem correct to drop the check for bit 5 on LTC3883. Maybe remove the if() above and always check for bit 5 and 6 ? Or should bit 4 be checked on parts other than LTC3883 ? #define LTC_NOT_TRANSITIONING BIT(4) ... mask = LTC_NOT_BUSY | LTC_NOT_PENDING; if (data->id != ltc3883) mask |= LTC_NOT_TRANSITIONING; Thanks, Guenter