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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 08ADFEE49AC for ; Sat, 19 Aug 2023 12:22:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232362AbjHSMWE (ORCPT ); Sat, 19 Aug 2023 08:22:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39756 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232334AbjHSMWD (ORCPT ); Sat, 19 Aug 2023 08:22:03 -0400 Received: from mail-pf1-x42c.google.com (mail-pf1-x42c.google.com [IPv6:2607:f8b0:4864:20::42c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8728A5EC; Sat, 19 Aug 2023 05:19:22 -0700 (PDT) Received: by mail-pf1-x42c.google.com with SMTP id d2e1a72fcca58-688731c6331so1387298b3a.3; Sat, 19 Aug 2023 05:19:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1692447562; x=1693052362; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=Zi3fLIF3cGkVGZeEalT4geZlr93ZgMT5amDrzmJ86OY=; b=At99HNtuapecOOibNo6Xw4mNJPidJtHCQdgdpFupob2NHTpTOp/Tp6KL4z80/bpX6N hPHMs0A9SkMEZo7SuqLoG51Rn+Ro1MPk3R93YBnRb8lUw9j4G0++aedCJ6UF+i9bZ6vc KGFwu5fZHQtm+9/8XVlUvRYIrjX2mHkbSESMLQPf1TIOYP6Yyaz95ym7bCn1bxHrzg4b U+Wc7wnrEdy85xtmT8bNRxGmSE0FPucw3K4me3GQaa7K4ru7YWKtmDu8K8XpEazoakVi 7q5pWzshLb6W96IzAdrAwQL5PxvpAkhVMm0yVAE60HHm6UcVYXFZjApLzeLgFmWQbrNQ 8bXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1692447562; x=1693052362; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=Zi3fLIF3cGkVGZeEalT4geZlr93ZgMT5amDrzmJ86OY=; b=BdhrE0NAM93L6mvoVKlhPWrhZj2E7a/yHLmLDTt5kV/UyFjUvequWENn65QpH1Ltku 1jo4I3nEfFDm25av0x1a/IXbWf7MsK+RHcsVlyTUWgFpgnJIKTL1bZM0B31u/lHC4h0j kXEb7wMknZ9muXz14HufCxOW+Zlu+aJq2KYet/5JSJTaTFlDdMvX0oyL/rDVRTy8VX4e oU27kFTwVMtXZcJIPr5R1dLCXr7n255EN82uzEdN6sSw0UCxXVT/gJiDbb23vlejQ17a w7JYsUgUEyZpTKBhQLUdI6iLGT3heIrW7hn0ibrCdx93SUD6BGgX4cpAVcyKWoFvPqYT 20GA== X-Gm-Message-State: AOJu0YzBn9rHg0YPGyHCfhRdKPGWOxw1LUxMdHOvrNR0F6NqLtY8+6Fu YimgOMweKR2hTmU2ROisDOTwj9mrutY= X-Google-Smtp-Source: AGHT+IH2ZoDgEZsGdXUAYiSmLcOV0RHSayrQCyb1RFijJsXGT/RtxCGa9Llls0ynFR1Z+OASSf283w== X-Received: by 2002:a05:6a20:8f09:b0:137:2281:944f with SMTP id b9-20020a056a208f0900b001372281944fmr1738987pzk.40.1692447562160; Sat, 19 Aug 2023 05:19:22 -0700 (PDT) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id h8-20020a170902ac8800b001b80de83b10sm3506628plr.301.2023.08.19.05.19.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 19 Aug 2023 05:19:21 -0700 (PDT) Sender: Guenter Roeck Date: Sat, 19 Aug 2023 05:19:20 -0700 From: Guenter Roeck To: Naresh Solanki Cc: Jean Delvare , Patrick Rudolph , linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] hwmon: pmbus: Fix -EIO seen on pli1209 Message-ID: References: <20230817092527.808631-1-Naresh.Solanki@9elements.com> <20230817092527.808631-3-Naresh.Solanki@9elements.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230817092527.808631-3-Naresh.Solanki@9elements.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 17, 2023 at 11:25:26AM +0200, Naresh Solanki wrote: > From: Patrick Rudolph > > After doing performance optimizations the pli1209 driver failed to > probe with a probabilty of 2%. It wasn't able to read the PMBUS_OPERATION > register due to an -EIO error. > > An investigation showed that the PLI1209 takes 230 usec to execute the > CLEAR_FAULTS command. During that time it's busy and NACKs all requests > on the SMBUS interface. It also NACKs reads on PMBUS_STATUS_BYTE > making it impossible to poll the BUSY flag. > > Add a custom write_data function to just wait for not BUSY unconditionally > after sending a CLEAR_FAULTS command. > > TEST: Verified using an I2C bus analyser that no more NACKs are seen after > sending a CLEAR_FAULTS command. > > Signed-off-by: Patrick Rudolph > Signed-off-by: Naresh Solanki Applied. Thanks, Guenter > --- > drivers/hwmon/pmbus/pli1209bc.c | 26 ++++++++++++++++++++++++++ > 1 file changed, 26 insertions(+) > > diff --git a/drivers/hwmon/pmbus/pli1209bc.c b/drivers/hwmon/pmbus/pli1209bc.c > index 7d8bd3167b21..c95433790b11 100644 > --- a/drivers/hwmon/pmbus/pli1209bc.c > +++ b/drivers/hwmon/pmbus/pli1209bc.c > @@ -5,6 +5,7 @@ > * Copyright (c) 2022 9elements GmbH > */ > > +#include > #include > #include > #include > @@ -53,6 +54,30 @@ static int pli1209bc_read_word_data(struct i2c_client *client, int page, > } > } > > +static int pli1209bc_write_byte(struct i2c_client *client, int page, u8 reg) > +{ > + int ret; > + > + switch (reg) { > + case PMBUS_CLEAR_FAULTS: > + ret = pmbus_write_byte(client, page, reg); > + /* > + * PLI1209 takes 230 usec to execute the CLEAR_FAULTS command. > + * During that time it's busy and NACKs all requests on the > + * SMBUS interface. It also NACKs reads on PMBUS_STATUS_BYTE > + * making it impossible to poll the BUSY flag. > + * > + * Just wait for not BUSY unconditionally. > + */ > + usleep_range(250, 300); > + break; > + default: > + ret = -ENODATA; > + break; > + } > + return ret; > +} > + > #if IS_ENABLED(CONFIG_SENSORS_PLI1209BC_REGULATOR) > static const struct regulator_desc pli1209bc_reg_desc = { > .name = "vout2", > @@ -102,6 +127,7 @@ static struct pmbus_driver_info pli1209bc_info = { > | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP > | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_INPUT, > .read_word_data = pli1209bc_read_word_data, > + .write_byte = pli1209bc_write_byte, > #if IS_ENABLED(CONFIG_SENSORS_PLI1209BC_REGULATOR) > .num_regulators = 1, > .reg_desc = &pli1209bc_reg_desc,