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 28F79C38147 for ; Wed, 18 Jan 2023 17:04:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229655AbjARRER (ORCPT ); Wed, 18 Jan 2023 12:04:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37458 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229499AbjARREO (ORCPT ); Wed, 18 Jan 2023 12:04:14 -0500 Received: from smtp-relay-internal-0.canonical.com (smtp-relay-internal-0.canonical.com [185.125.188.122]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4421C1716E for ; Wed, 18 Jan 2023 09:04:13 -0800 (PST) Received: from mail-pl1-f200.google.com (mail-pl1-f200.google.com [209.85.214.200]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-internal-0.canonical.com (Postfix) with ESMTPS id ED6433F124 for ; Wed, 18 Jan 2023 17:04:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1674061450; bh=5SYtdRB0wOm4T2jCfMhlLtgKk9wbubyH9yWyonQFCeo=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=HegGUkjwxA1EbOcPrm0roQ/sUaAVTKtyjIgM3k5cNz1C9EFPdYt1zLgHsFkT0FZka DJ6bZipC6OcMOz22H4NvICYgsfbJiS4dabuUMEELlFRLF7ra31pxXjutPofGaF7CxM bwHxz616ko0Ixp4I0FqXcNwzc0NOSBYSIgf1lOmUE6DPs9fHuiKHJNAVRb3cz0TSkk wyiz0muh94Vyh6d2oLnpqDueQ4GQt7P3bitRoype45UQGxDc7cE6ddgr1K6Cc8QR0s bx9fBLcDIJDKAqNJTbIcbpCUNNWDpsrRSCSZj7XS+69JHgJDFfVz+jLm15MyWnZ+pX L8C/5bgtUFXRQ== Received: by mail-pl1-f200.google.com with SMTP id i16-20020a17090332d000b00194a7b146b2so3562085plr.20 for ; Wed, 18 Jan 2023 09:04:10 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=5SYtdRB0wOm4T2jCfMhlLtgKk9wbubyH9yWyonQFCeo=; b=KvIyMzZgC6caodpSvetHm+ngj2NrIP3UfWpK5+yO5TMLyzObZE4txe6THaBKsEiHiU XjsgAQBQzmTEiSu6VZ7oEgXsAapgyWhMzL/Jwg9o+7TjOBqqGXYIJwjLX/yoTuGsFTkt CoaxOWWc4NNe1qRSAm2t0OTD4jp65oKVfff9dXHSCmshqeEkbzSQH446yMbRzucrMHZy TeqoBGVrlwVBRvjFLtsm4KxpYWCR4JVo1hReB/ofD1vwMAVCd9tkvG88Mi+VrtvlCDcU fJjjj4D3WBCUKgb9sP6tJnpRkUhUcX7m6dMf7po4D7DS6AEu+aVNxDSs/GkPm7MNUeFt dbJQ== X-Gm-Message-State: AFqh2krN/5kdq/y45n6INerixeu/wjIxRgMsgv9gNDucppSwI4iMhqcz 3AhVk334aoOa3dYu7TNxZv0/kZgWvnS2+NbwnSIkQR15Uwiq40LzfHPF0FmRVoE0bkGg5QeCprk pUKVFGV1ETeMOXdmD5Vo2i7emQBPOSY4GXsFp8FQLN/V2o5BPaBpiPYrZow== X-Received: by 2002:a63:5303:0:b0:478:ac4b:bd6f with SMTP id h3-20020a635303000000b00478ac4bbd6fmr542410pgb.435.1674061449271; Wed, 18 Jan 2023 09:04:09 -0800 (PST) X-Google-Smtp-Source: AMrXdXtrcuIx8bawaThYbiDoMBBBOPRIMttzcMSs8VmThqWTbakfGUwSQOMEf/UWj3WSAs0YIONYFcA8sDM/WU8GNz4= X-Received: by 2002:a63:5303:0:b0:478:ac4b:bd6f with SMTP id h3-20020a635303000000b00478ac4bbd6fmr542402pgb.435.1674061448883; Wed, 18 Jan 2023 09:04:08 -0800 (PST) MIME-Version: 1.0 References: <20230117160951.282581-1-kai.heng.feng@canonical.com> <5c95d25b-ff26-053b-efc8-5f6fd979c7e2@redhat.com> In-Reply-To: From: Kai-Heng Feng Date: Thu, 19 Jan 2023 01:03:57 +0800 Message-ID: Subject: Re: [PATCH] iio: light: cm32181: Fix PM support on system with 2 I2C resources To: Hans de Goede Cc: ktsai@capellamicro.com, jic23@kernel.org, lars@metafoo.de, Wahaj , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Hans, On Wed, Jan 18, 2023 at 6:52 PM Hans de Goede wrote: > > Hi, > > On 1/18/23 06:15, Kai-Heng Feng wrote: > > On Wed, Jan 18, 2023 at 11:29 AM Kai-Heng Feng > > wrote: > >> > >> Hi Hans, > >> > >> On Wed, Jan 18, 2023 at 1:21 AM Hans de Goede wrote: > >>> > >>> Hi, > >>> > >>> On 1/17/23 17:09, Kai-Heng Feng wrote: > >>>> Commit c1e62062ff54 ("iio: light: cm32181: Handle CM3218 ACPI devices > >>>> with 2 I2C resources") creates a second client for the actual I2C > >>>> address, but the "struct device" passed to PM ops is the first client > >>>> that can't talk to the sensor. > >>>> > >>>> That means the I2C transfers in both suspend and resume routines can > >>>> fail and blocking the whole suspend process. > >>>> > >>>> Instead of using the first client for I2C transfer, store the cm32181 > >>>> private struct on both cases so the PM ops can get the correct I2C > >>>> client to perfrom suspend and resume. > >>>> > >>>> Fixes: 68c1b3dd5c48 ("iio: light: cm32181: Add PM support") > >>>> Tested-by: Wahaj > >>>> Signed-off-by: Kai-Heng Feng > >>> > >>> Thank you for this fix. I had looking into this on my todo list, > >>> since I have been seeing some bug reports about this too. > >>> > >>> One remark inline: > >>> > >>>> --- > >>>> drivers/iio/light/cm32181.c | 11 +++++++---- > >>>> 1 file changed, 7 insertions(+), 4 deletions(-) > >>>> > >>>> diff --git a/drivers/iio/light/cm32181.c b/drivers/iio/light/cm32181.c > >>>> index 001055d097509..0f319c891353c 100644 > >>>> --- a/drivers/iio/light/cm32181.c > >>>> +++ b/drivers/iio/light/cm32181.c > >>>> @@ -440,6 +440,8 @@ static int cm32181_probe(struct i2c_client *client) > >>>> if (!indio_dev) > >>>> return -ENOMEM; > >>>> > >>>> + i2c_set_clientdata(client, indio_dev); > >>>> + > >>> > >>> Why move this up, the suspend/resume callbacks cannot run until > >>> probe() completes, so no need for this change. > >> > >> The intention is to save indio_dev as drvdata in the first (i.e. > >> original) i2c_client's dev. > >> > >>> > >>>> /* > >>>> * Some ACPI systems list 2 I2C resources for the CM3218 sensor, the > >>>> * SMBus Alert Response Address (ARA, 0x0c) and the actual I2C address. > >>>> @@ -458,9 +460,9 @@ static int cm32181_probe(struct i2c_client *client) > >>>> client = i2c_acpi_new_device(dev, 1, &board_info); > >>>> if (IS_ERR(client)) > >>>> return PTR_ERR(client); > >>>> - } > >>>> > >>>> - i2c_set_clientdata(client, indio_dev); > >>>> + i2c_set_clientdata(client, indio_dev); > >>>> + } > >>> > >>> And moving it inside the if block here (instead of just dropping it) > >>> is also weird. I guess you meant to just delete it since you moved it up. > >> > >> Doesn't i2c_acpi_new_device() creates a new i2c_client (and its dev embedded)? > >> > >> So the intention is to save indio_dev for the second (ARA case) i2c_client too. > >> > >>> > >>>> > >>>> cm32181 = iio_priv(indio_dev); > >>>> cm32181->client = client; > >>> > >>> Also note that the ->client used in suspend/resume now is not set until > >>> here, so moving the i2c_set_clientdata() up really does not do anything. > >>> > >>> I beleive it would be best to just these 2 hunks from the patch and > >>> only keep the changes to the suspend/resume callbacks. > >> > >> Yes, it seems like those 2 hunks are not necessary. Let me send a new patch. > > > > if (ACPI_HANDLE(dev) && client->addr == SMBUS_ALERT_RESPONSE_ADDRESS) { > > ... > > client = i2c_acpi_new_device(dev, 1, &board_info); > > ... > > } > > i2c_set_clientdata(client, indio_dev); > > > > It means the indio_dev is only assigned to the new i2c_client->dev's > > drvdata, the original dev's drvdata remains NULL. > > So we need to assign it before the original client gets replaced by > > the new one, otherwise we can't get cm32181 in PM ops. > > You are right, my bad. The original code has a bug where it indeed was > making the i2c_set_clientdata() call on the wrong client device. > > So the i2c_set_clientdata() call needs to be moved up. > > There is no need to also call i2c_set_clientdata() on the dummy > i2c-client though. That one does not have a driver attached. Sure, will update this in v2. > > The suspend/resume callbacks are made on the original client-dev, > not on the one of the dummy-client (which is the one which we > actually use to communicate). > > >> But I do wonder what happens for the removing case? Will the second > >> i2c_client leak? > > Yes it does, good point. That should probably also be fixed, but > that needs to be a different / second patch. Agree, thanks for the input. Kai-Heng > > Regards, > > Hans > > > > >>>> @@ -490,7 +492,8 @@ static int cm32181_probe(struct i2c_client *client) > >>>> > >>>> static int cm32181_suspend(struct device *dev) > >>>> { > >>>> - struct i2c_client *client = to_i2c_client(dev); > >>>> + struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev)); > >>>> + struct i2c_client *client = cm32181->client; > >>>> > >>>> return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD, > >>>> CM32181_CMD_ALS_DISABLE); > >>>> @@ -498,8 +501,8 @@ static int cm32181_suspend(struct device *dev) > >>>> > >>>> static int cm32181_resume(struct device *dev) > >>>> { > >>>> - struct i2c_client *client = to_i2c_client(dev); > >>>> struct cm32181_chip *cm32181 = iio_priv(dev_get_drvdata(dev)); > >>>> + struct i2c_client *client = cm32181->client; > >>>> > >>>> return i2c_smbus_write_word_data(client, CM32181_REG_ADDR_CMD, > >>>> cm32181->conf_regs[CM32181_REG_ADDR_CMD]); > >>> > > >