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 5C8B4C46467 for ; Tue, 3 Jan 2023 17:40:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233409AbjACRkO (ORCPT ); Tue, 3 Jan 2023 12:40:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40772 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238253AbjACRkM (ORCPT ); Tue, 3 Jan 2023 12:40:12 -0500 Received: from mail-oa1-x32.google.com (mail-oa1-x32.google.com [IPv6:2001:4860:4864:20::32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CC91C10FFF; Tue, 3 Jan 2023 09:40:08 -0800 (PST) Received: by mail-oa1-x32.google.com with SMTP id 586e51a60fabf-14ffd3c5b15so26041927fac.3; Tue, 03 Jan 2023 09:40:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; 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=cMNfeSjCh0BfCORHZrZEG9uctt5EKtuv6ubYw+95YrQ=; b=fm71vNWnwQQHOfPakKRsYfmPoBLDYAw3ctA/PF+HT9ICdhbnGIQNYGMmkUw9GyAuHg IbZTvYgBweMemgOW43AYk1BY/ymFH7gCsd8OEcatJ8MMhGny8fORmKvanUBGMwXQzmHy LN5dc7a9M8rWUEdVNM8DKA3Vw6H4GWxTv28Uh6wRXE1KcNplob7d7q0G33Tm3PjaYNXR ARIdwd1tF3UX6QmqdRPxhqG9CQpP1Q9Q9ItfCiOSFdHSreFl9V1NSSMo6zKIT9VRkPpi 7Css/CDwbSFotuEUqQwCx0eSikbL/KFSw9N/ZnudxBZRodEXH/iyv2goEofDbqquEyM1 REEw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; 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=cMNfeSjCh0BfCORHZrZEG9uctt5EKtuv6ubYw+95YrQ=; b=IvdDxr+Q/AXLZzMil6Zmk8I3I8c57pgi5J6kepGovcCIh/FFgfuZbncDlP+ugPdoPr qpnHCGxcsFYrAn1SihpLyP94DEEZz/OuvKnmpRaxxTb8CatKlgYBiKhaezHNVxUyoZXV VJDIFMQg5EJdOp0KDnfGpynm7RNf78EPh1672ATuXzPkZXirzI2+m2oIWglrqUZKLJtD PRRIhIXyU4pyb9vEylpHuDK0JCAqsTdgkmoq4HNev2UOyF7DUZXJqIXiDEUW1Ri5tBzy MRXsnlQQz2SkSiIOpEc7nSV18dGnUpQFGX2X0Nw/gCOtRRKo+DeNljiuYEo4sgrgnwil ZH1A== X-Gm-Message-State: AFqh2kqldeF7dy2MNzoCDxIvZ5EgkqAule3DSe9CMo3Ppj7MUcmRkOO2 KaDGQs3EEwx2Itzxw/foR9mrUSQzB8A= X-Google-Smtp-Source: AMrXdXtC7utx+3MwR6P3tvbWfL40qQV0qB9AIJ2x6aWpB+sMLmruy2V+jnlYzmuedmnBhvyrf2IDVQ== X-Received: by 2002:a05:6870:cd04:b0:13b:8098:d195 with SMTP id qk4-20020a056870cd0400b0013b8098d195mr19013960oab.27.1672767607277; Tue, 03 Jan 2023 09:40:07 -0800 (PST) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id n38-20020a05687055a600b0013b9ee734dcsm14450344oao.35.2023.01.03.09.40.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 03 Jan 2023 09:40:06 -0800 (PST) Sender: Guenter Roeck Date: Tue, 3 Jan 2023 09:40:04 -0800 From: Guenter Roeck To: Naresh Solanki Cc: devicetree@vger.kernel.org, Jean Delvare , Liam Girdwood , Mark Brown , linux-kernel@vger.kernel.org, linux-hwmon@vger.kernel.org, Patrick Rudolph Subject: Re: [PATCH RESEND v6 1/5] hwmon: (pmbus/core): Add interrupt support Message-ID: <20230103174004.GA202902@roeck-us.net> References: <20221214080715.2700442-1-Naresh.Solanki@9elements.com> <20221229144012.GA21213@roeck-us.net> <20230103122656.GB190111@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Tue, Jan 03, 2023 at 08:56:59PM +0530, Naresh Solanki wrote: > Hi Guenter > > On 03-01-2023 05:56 pm, Guenter Roeck wrote: > > On Tue, Jan 03, 2023 at 12:18:49PM +0530, Naresh Solanki wrote: > > > Hi Guenter, > > > > > > On 29-12-2022 08:10 pm, Guenter Roeck wrote: > > > > On Wed, Dec 14, 2022 at 09:07:11AM +0100, Naresh Solanki wrote: > > > > > From: Patrick Rudolph > > > > > > > > > > Implement PMBUS irq handler. > > > > > > > > > > Signed-off-by: Patrick Rudolph > > > > > Signed-off-by: Naresh Solanki > > > > > > > > $ scripts/checkpatch.pl --strict index.html > > > > CHECK: Blank lines aren't necessary after an open brace '{' > > > > #131: FILE: drivers/hwmon/pmbus/pmbus_core.c:3088: > > > > + for (i = 0; i < data->info->pages; i++) { > > > > + > > > > > > > > CHECK: Alignment should match open parenthesis > > > > #183: FILE: drivers/hwmon/pmbus/pmbus_core.c:3140: > > > > + ret = devm_request_threaded_irq(dev, client->irq, NULL, pmbus_fault_handler, > > > > + 0, "pmbus-irq", data); > > > > > > > > CHECK: Please use a blank line after function/struct/union/enum declarations > > > > #197: FILE: drivers/hwmon/pmbus/pmbus_core.c:3154: > > > > } > > > > +static int pmbus_irq_setup(struct i2c_client *client, struct pmbus_data *data) > > > > > > > > total: 0 errors, 0 warnings, 3 checks, 109 lines checked > > > > > > > > NOTE: For some of the reported defects, checkpatch may be able to > > > > mechanically convert to the typical style using --fix or --fix-inplace. > > > > > > > > index.html has style problems, please review. > > > > > > > > Please run checkpatch --strict on your patches. > > > > Also see Documentation/hwmon/submitting-patches.rst. > > > I will take care of these errors in the updated version. > > > > > > > > > --- > > > > > drivers/hwmon/pmbus/pmbus.h | 2 +- > > > > > drivers/hwmon/pmbus/pmbus_core.c | 84 ++++++++++++++++++++++++++++++++ > > > > > 2 files changed, 85 insertions(+), 1 deletion(-) > > > > > > > > > > > > > > > base-commit: 364ffd2537c44cb6914ff5669153f4a86fffad29 > > > > > > > > > > diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h > > > > > index 10fb17879f8e..6b2e6cf93b19 100644 > > > > > --- a/drivers/hwmon/pmbus/pmbus.h > > > > > +++ b/drivers/hwmon/pmbus/pmbus.h > > > > > @@ -26,7 +26,7 @@ enum pmbus_regs { > > > > > PMBUS_CAPABILITY = 0x19, > > > > > PMBUS_QUERY = 0x1A, > > > > > - > > > > > + PMBUS_SMBALERT_MASK = 0x1B, > > > > > PMBUS_VOUT_MODE = 0x20, > > > > > PMBUS_VOUT_COMMAND = 0x21, > > > > > PMBUS_VOUT_TRIM = 0x22, > > > > > diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c > > > > > index 95e95783972a..244fd2597252 100644 > > > > > --- a/drivers/hwmon/pmbus/pmbus_core.c > > > > > +++ b/drivers/hwmon/pmbus/pmbus_core.c > > > > > @@ -3072,11 +3072,89 @@ static int pmbus_regulator_register(struct pmbus_data *data) > > > > > return 0; > > > > > } > > > > > + > > > > > +static int pmbus_write_smbalert_mask(struct i2c_client *client, u8 page, u8 reg, u8 val) > > > > > +{ > > > > > + return pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8)); > > > > > +} > > > > > + > > > > > +static irqreturn_t pmbus_fault_handler(int irq, void *pdata) > > > > > +{ > > > > > + struct pmbus_data *data = pdata; > > > > > + struct i2c_client *client = to_i2c_client(data->dev); > > > > > + int i, status; > > > > > + > > > > > + for (i = 0; i < data->info->pages; i++) { > > > > > + > > > > > + mutex_lock(&data->update_lock); > > > > > + status = pmbus_read_status_word(client, i); > > > > > + if (status < 0) { > > > > > + mutex_unlock(&data->update_lock); > > > > > + return status; > > > > > + } > > > > > + > > > > > + if (status & ~(PB_STATUS_OFF | PB_STATUS_BUSY | PB_STATUS_POWER_GOOD_N)) > > > > > + pmbus_clear_fault_page(client, i); > > > > > + > > > > > + mutex_unlock(&data->update_lock); > > > > > + } > > > > > + > > > > > + return IRQ_HANDLED; > > > > > +} > > > > > + > > > > > +static int pmbus_irq_setup(struct i2c_client *client, struct pmbus_data *data) > > > > > +{ > > > > > + struct device *dev = &client->dev; > > > > > + const struct pmbus_regulator_status_category *cat; > > > > > + const struct pmbus_regulator_status_assoc *bit; > > > > > + int i, j, err, ret, func; > > > > > + u8 mask; > > > > > + > > > > > + for (i = 0; i < data->info->pages; i++) { > > > > > + func = data->info->func[i]; > > > > > + > > > > > + for (j = 0; j < ARRAY_SIZE(pmbus_regulator_flag_map); j++) { > > > > > + cat = &pmbus_regulator_flag_map[j]; > > > > > + if (!(func & cat->func)) > > > > > + continue; > > > > > + mask = 0; > > > > > + for (bit = cat->bits; bit->pflag; bit++) > > > > > + mask |= bit->pflag; > > > > > + > > > > > + err = pmbus_write_smbalert_mask(client, i, cat->reg, ~mask); > > > > > + if (err) > > > > > + dev_err(dev, "Failed to set smbalert for reg 0x%02x\n", cat->reg); > > > > > > > > This concerns me. It might mean that the chip does not support > > > > PMBUS_SMBALERT_MASK. If so, there would be lots of error messages. > > > After going through the PMBus specification, it appears that this should not > > > be an issue unless there is a violation of the specification. > > > > PMBus chips have lots of issues which violate the specification. > > Have a look at the various drivers and the workarounds implemented there. > > You'll need to check if the command/register is supported before using it. > > Also, if you want to keep the error message, make it dev_err_once(). > > > > Either case, an error is an error, not to be ignored. An error here > > should result in an error abort. > Yes, I agree that PMBus chips can have issues that violate the > specification, and that it is important to check whether a command or > register is supported before using it. > I have noticed that many drivers use the PMBUS_HAVE_* flags to expose the > presence of specific registers, and I think it would be a good idea to add a > PMBUS_HAVE_SMBALERT flag as well, so that drivers for supported chips can > use it to determine whether they should set up an IRQ handler or not. If > PMBUS_HAVE_SMBALERT is set, then the IRQ handler should be set up, otherwise > it should be ignored. > Will this approach be right? Not really. PMBUS_HAVE_ flags are intended to indicate sensor register support, not to indicate compliance problems. What you'd be looking for would be the flags in struct pmbus_platform_data. However, those are only intended to be used if registers/commands can not be auto-detected or if doing so causes problems. See include/linux/pmbus.h for details. Unless there is reason to believe that chips are misbehaving when trying to read from or to set PMBUS_SMBALERT_MASK, we should stick with auto- detection. After all, that is what pmbus_check_{status,byte,word}_register() functions are for. Thanks, Guenter