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=-6.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 214D9C2D0DB for ; Wed, 29 Jan 2020 13:54:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DDB812071E for ; Wed, 29 Jan 2020 13:54:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=baylibre-com.20150623.gappssmtp.com header.i=@baylibre-com.20150623.gappssmtp.com header.b="UUQJmVe3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726385AbgA2Nyc (ORCPT ); Wed, 29 Jan 2020 08:54:32 -0500 Received: from mail-qk1-f194.google.com ([209.85.222.194]:43732 "EHLO mail-qk1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726271AbgA2Nyc (ORCPT ); Wed, 29 Jan 2020 08:54:32 -0500 Received: by mail-qk1-f194.google.com with SMTP id j20so17020750qka.10 for ; Wed, 29 Jan 2020 05:54:31 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baylibre-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=rYOGFr9wS3HXrXEfVL8jpzDCtWVLlGedKrOARmVJi80=; b=UUQJmVe3RNHr2pAk/tALeA720imfjRHs47ntw1zXz/kqNcwGoBQC0PW8D06qV2Oidm /3hAlVbIi6jc7HbqeOijLyabl+P6omrNVI4SgR2SXGbNIdgYn0c/nvixNsABMaqxeN89 m5GAYxhLMy5VIPizb7/fIzdcW9JxzCEUq2OCLvEFDdIdJKZEDYiSzdiuSdf70G6m3+lw OCRpUjx8T2h2/G5TP2qnwqTl04kx4ceG7lNSbFP36iNl9n4KIgVlA3bvC3DjjagYfBaN /HgiR6xceYivvrVJl9b9e6/vrS5oZuMhvT08M5F2bjiJZz15F3bzgXcW2kEOvSTtYtN4 r9vQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=rYOGFr9wS3HXrXEfVL8jpzDCtWVLlGedKrOARmVJi80=; b=GkRNFi32W99nirNbargUQcUavXQ8Vq5/CjC1x2ZiW48n5NKAtQ2PAnMdJpuv1HFPry 3ozkRtBE5MA1/11Jc5XQ2pIWoIxzeSIbuTLkkLdZadT0p4bcgkd6f2PVfIHyWKXO7s/S h0TxT7RwM8gXhvgas6buYbzYfilpJrfQUQzRUtOZ4lm5uzvxU5EZzdz4DY0QyXaRd0Bd syKHOJ4nVko2y5EhciLD9lNn7sW7hctd5PbxdHAzQXpZcmKzcVfYsKEAxMJ2MBXQlUl3 ogA3SmKXO+5PvjrDnQ5w/C3Wuj37vl3650yxjNITWZ80u/y5oFE2jfPKFO3FhrJUcr9g OrwA== X-Gm-Message-State: APjAAAVxOKQVSBuwIITNku2fknwDcLWRJnkmRY8ZXeEvf2oFG/dxSEsE cUKgscPmVYblvbMsrFpSlBBIzfC0BrPwCpbbZFdYlA== X-Google-Smtp-Source: APXvYqxBEm4xJ6kv4arA/On09OUECl7DMlqvpUATSIKO8jSWyETC4I0SLTiOGIrDuIdF6CfuHSTxmM2f0fSLvrDBC7A= X-Received: by 2002:a05:620a:12cf:: with SMTP id e15mr28371679qkl.120.1580306071128; Wed, 29 Jan 2020 05:54:31 -0800 (PST) MIME-Version: 1.0 References: <20200121134157.20396-1-sakari.ailus@linux.intel.com> <20200121134157.20396-2-sakari.ailus@linux.intel.com> In-Reply-To: <20200121134157.20396-2-sakari.ailus@linux.intel.com> From: Bartosz Golaszewski Date: Wed, 29 Jan 2020 14:54:20 +0100 Message-ID: Subject: Re: [PATCH v4 1/6] i2c: Allow driver to manage the device's power state during probe To: Sakari Ailus Cc: linux-i2c , Wolfram Sang , "Rafael J. Wysocki" , linux-acpi@vger.kernel.org, Bingbu Cao , linux-media , Chiranjeevi Rapolu , Hyungwoo Yang , Arnd Bergmann , LKML , Greg Kroah-Hartman , rajmohan.mani@intel.com, Tomasz Figa Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org wt., 21 sty 2020 o 14:41 Sakari Ailus napisa= =C5=82(a): > > Enable drivers to tell ACPI that there's no need to power on a device for > probe. Drivers should still perform this by themselves if there's a need > to. In some cases powering on the device during probe is undesirable, and > this change enables a driver to choose what fits best for it. > > Signed-off-by: Sakari Ailus > --- > drivers/i2c/i2c-core-base.c | 15 ++++++++++++--- > include/linux/i2c.h | 3 +++ > 2 files changed, 15 insertions(+), 3 deletions(-) > > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c > index 9f8dcd3f83850..7bf1699c9044d 100644 > --- a/drivers/i2c/i2c-core-base.c > +++ b/drivers/i2c/i2c-core-base.c > @@ -303,6 +303,14 @@ static int i2c_smbus_host_notify_to_irq(const struct= i2c_client *client) > return irq > 0 ? irq : -ENXIO; > } > > +static bool probe_low_power(struct device *dev) > +{ > + struct i2c_driver *driver =3D to_i2c_driver(dev->driver); > + > + return driver->probe_low_power && > + device_property_present(dev, "probe-low-power"); > +} > + > static int i2c_device_probe(struct device *dev) > { > struct i2c_client *client =3D i2c_verify_client(dev); > @@ -375,7 +383,8 @@ static int i2c_device_probe(struct device *dev) > if (status < 0) > goto err_clear_wakeup_irq; > > - status =3D dev_pm_domain_attach(&client->dev, true); > + status =3D dev_pm_domain_attach(&client->dev, > + !probe_low_power(&client->dev)); > if (status) > goto err_clear_wakeup_irq; > > @@ -397,7 +406,7 @@ static int i2c_device_probe(struct device *dev) > return 0; > > err_detach_pm_domain: > - dev_pm_domain_detach(&client->dev, true); > + dev_pm_domain_detach(&client->dev, !probe_low_power(&client->dev)= ); > err_clear_wakeup_irq: > dev_pm_clear_wake_irq(&client->dev); > device_init_wakeup(&client->dev, false); > @@ -419,7 +428,7 @@ static int i2c_device_remove(struct device *dev) > status =3D driver->remove(client); > } > > - dev_pm_domain_detach(&client->dev, true); > + dev_pm_domain_detach(&client->dev, !probe_low_power(&client->dev)= ); > > dev_pm_clear_wake_irq(&client->dev); > device_init_wakeup(&client->dev, false); > diff --git a/include/linux/i2c.h b/include/linux/i2c.h > index 582ef05ec07ed..6d0d6af393c56 100644 > --- a/include/linux/i2c.h > +++ b/include/linux/i2c.h > @@ -229,6 +229,8 @@ enum i2c_alert_protocol { > * @address_list: The I2C addresses to probe (for detect) > * @clients: List of detected clients we created (for i2c-core use only) > * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mappin= g > + * @probe_low_power: Let the driver manage the device's power state > + * during probe and remove. > * > * The driver.owner field should be set to the module owner of this driv= er. > * The driver.name field should be set to the name of this driver. > @@ -289,6 +291,7 @@ struct i2c_driver { > struct list_head clients; > > bool disable_i2c_core_irq_mapping; > + bool probe_low_power; I don't see any users of disable_i2c_core_irq_mapping in current mainline. Maybe instead of adding another 1-byte boolean for every such property, let's just use the fact that this struct will have at least an alignment of 32-bits anyway and merge the two into an int field called 'flags' so that we can extend it in the future if needed? The name 'probe_low_power' is misleading to me too. It makes me think it's the default state for some reason. It should be something like 'allow_low_power_probe'. Bartosz > }; > #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) > > -- > 2.20.1 >