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=-9.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 67E6EC433DB for ; Tue, 9 Feb 2021 16:59:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1100964EB4 for ; Tue, 9 Feb 2021 16:59:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232812AbhBIQ7L (ORCPT ); Tue, 9 Feb 2021 11:59:11 -0500 Received: from mail-ot1-f49.google.com ([209.85.210.49]:35876 "EHLO mail-ot1-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233188AbhBIQ7F (ORCPT ); Tue, 9 Feb 2021 11:59:05 -0500 Received: by mail-ot1-f49.google.com with SMTP id 100so11396486otg.3; Tue, 09 Feb 2021 08:58:49 -0800 (PST) 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; bh=evwy4XV5Q6cMll0/XuL/bVl96ksA3QLEns1+sYmoTko=; b=msLssMkS3mLEqo3lzNMaZmG7yIvC9a30/M8DsEwcgajyOZvAPsnVp0tewctsqxgahR LoEyvqnnIK3owx3TJZeB3MEq+6OjHNkM0+MfFEhTT5xkgRM6wQ+nfrq6VkBKMqFAXUCt IWINXbSFoea0Wgtt1lm95RJIAA1lfmFx5KgsyjjHuXICOZELX6RBF3f5hStf3hJZRrV1 yhdAtG70f5da8ak9ze8KqlnTFsGureCJhVy7ZZU2/IFKq0WqfGs+QAstsQoKGsL55/bW uxUn0S9TkByhV2gtkYTjciGv9Sa5mQ/GJC1dmSc+Ho4BmcZdZsOMV3c8cUkYEhfmkz9Y 5gwQ== X-Gm-Message-State: AOAM531kHa3BkJ+E/VtpHib03OhOr1ugHcfzl+DsEUV9kUhxSrR9Izsd pVBpJZlN8+tgLzqSEgBVd8Wh4h9t86eMC+rS4lY= X-Google-Smtp-Source: ABdhPJyMo3OVcJErKwZDw1AwIpwz257KAaFbUa4mBXCtpt+3iOCDI+/o4eSo/qspDLxKuujPQMQhK2w4bFuvFd7JXto= X-Received: by 2002:a9d:a2d:: with SMTP id 42mr15389022otg.321.1612889903680; Tue, 09 Feb 2021 08:58:23 -0800 (PST) MIME-Version: 1.0 References: <20210205132505.20173-1-sakari.ailus@linux.intel.com> <20210205132505.20173-8-sakari.ailus@linux.intel.com> <20210209162343.GF32460@paasikivi.fi.intel.com> <20210209165418.GG32460@paasikivi.fi.intel.com> In-Reply-To: <20210209165418.GG32460@paasikivi.fi.intel.com> From: "Rafael J. Wysocki" Date: Tue, 9 Feb 2021 17:58:12 +0100 Message-ID: Subject: Re: [PATCH v10 7/7] at24: Support probing while off To: Sakari Ailus Cc: "Rafael J. Wysocki" , Bartosz Golaszewski , linux-i2c , Wolfram Sang , ACPI Devel Maling List , LKML , Greg Kroah-Hartman , Rajmohan Mani , Tomasz Figa , Bingbu Cao , Chiranjeevi Rapolu , Hyungwoo Yang , linux-media Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On Tue, Feb 9, 2021 at 5:54 PM Sakari Ailus wrote: > > On Tue, Feb 09, 2021 at 05:42:45PM +0100, Rafael J. Wysocki wrote: > > On Tue, Feb 9, 2021 at 5:23 PM Sakari Ailus > > wrote: > > > > > > Hi Bartosz, Rafael, > > > > > > On Tue, Feb 09, 2021 at 04:49:37PM +0100, Bartosz Golaszewski wrote: > > > > On Mon, Feb 8, 2021 at 5:54 PM Rafael J. Wysocki wrote: > > > > > > > > > > On Mon, Feb 8, 2021 at 5:44 PM Bartosz Golaszewski > > > > > wrote: > > > > > > > > > > > > On Fri, Feb 5, 2021 at 2:25 PM Sakari Ailus > > > > > > wrote: > > > > > > > > > > > > > > In certain use cases (where the chip is part of a camera module, and the > > > > > > > camera module is wired together with a camera privacy LED), powering on > > > > > > > the device during probe is undesirable. Add support for the at24 to > > > > > > > execute probe while being powered off. For this to happen, a hint in form > > > > > > > of a device property is required from the firmware. > > > > > > > > > > > > > > Signed-off-by: Sakari Ailus > > > > > > > Reviewed-by: Tomasz Figa > > > > > > > --- > > > > > > > > > > > > I'll ack this but I still claim that the name > > > > > > acpi_dev_state_low_power() is super misleading for this use-case and > > > > > > I've been saying that for 10 versions now with everyone just ignoring > > > > > > my remarks. :/ > > > > > > > > > > Well, the function in question simply checks if the current ACPI power > > > > > state of the device is different from "full power", so its name > > > > > appears to be quite adequate to me. > > > > > > > > > > If the way in which it is used is confusing, though, I guess > > > > > explaining what's going on would be welcome. > > > > > > > > > > > > > Yes, I have explained it multiple time already - last time at v9 of this series: > > > > > > > > https://www.spinics.net/lists/kernel/msg3816807.html > > > > > > How about adding this to the description of acpi_dev_state_low_power(): > > > > > > -----------8<-------------- > > > * This function is intended to be used by drivers to tell whether the device > > > * is in low power state (D1--D3cold) in driver's probe or remove function. See > > > * Documentation/firmware-guide/acpi/low-power-probe.rst for more information. > > > -----------8<-------------- > > > > This information is already there in the kerneldoc description of that > > function AFAICS. > > Ok, the D states are mentioned already. But how to use it is not, nor > there's a reference to the ReST file. I think that wouldn't hurt. > > > > > I was thinking about adding an explanation comment to the caller. > > I think it'd be best if the function name would convey that without a > comment that should then be added to all callers. How about calling the > function e.g. acpi_dev_state_d0() and negating the return value? The D0 > state is well defined and we could do this without adding new terms. That would work for me.