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=-8.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 37F94C433E9 for ; Wed, 10 Feb 2021 12:29:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0609564E5A for ; Wed, 10 Feb 2021 12:29:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231703AbhBJM3L (ORCPT ); Wed, 10 Feb 2021 07:29:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43522 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231814AbhBJM1p (ORCPT ); Wed, 10 Feb 2021 07:27:45 -0500 Received: from mail-ed1-x535.google.com (mail-ed1-x535.google.com [IPv6:2a00:1450:4864:20::535]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B5E4C061756 for ; Wed, 10 Feb 2021 04:27:04 -0800 (PST) Received: by mail-ed1-x535.google.com with SMTP id g10so2763027eds.2 for ; Wed, 10 Feb 2021 04:27:04 -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; bh=Phx2Df+hBBWF6//uqqDU9bgwk8wPxGzI8wPThN0e6e4=; b=XWEkebRiibdEdE+6ZB77pkBDh+47f7G/U8vuVdUs3ojDxrmD+oIRSWGm5kX5MXCP3L 8FOw4XysMFBMfDCFK8HdIucqIu9o0gChIV8kqjE01MFl65rUCpSPso/3leXmhQch2tYd O5bhkzF/tafxn+1JrQIFDtPYHfUVBDSm/vzvn6Semntf5QSpf3XIsRH6aPDS2FdzsriJ NyKxsx2ZIxSV/G0Q+hHt8Y5ofXa1XgUI4Z4Hz2UDxq3XrOD2IknCK8R+7oL5mdybpmU0 djiKokRfEBYKqIwNmiJsY9cG4LzSv8D6grvkhuaWb4XJeeE1D/StTKSbGG5UGVcxT8aU eQzA== 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=Phx2Df+hBBWF6//uqqDU9bgwk8wPxGzI8wPThN0e6e4=; b=mnCNiWl1NWr57VgJjjbBxevloM/50kwwZGuHVnhP48+B8UYzVxjF5lrUim5E2By3Mz x56NXPs9NWR+Erwc4+svzJWo/diTt1lJMJDva7IVxXBSIuhRHr/2I0rgkCwWmvat0Z0l JtxPE68hMGq1TqkEu7ErI+pf4o8jLJ49iRP1mA89P3UvXPKn/hn9xSKbalLWHRyMpEK7 ssj2awE066Ysu+TzbaPWsuUuiMU9+eQxiWGci0LDX9d19nfxJcKrSyNigRW/EWtSD6o+ 9Gvm28C6R0yeYy31yngnNVhZjZoRbtRebL0CVKTFZQs20QuOMdyuNwCn8RkI4tDPZ0Eb T4LA== X-Gm-Message-State: AOAM5313st/25zcwSiKLwnZwkuPm+5gC+wfawf6YQMlc75XB3DsRNYnC RfrXXNOFxxP3Y9ifpCJwrfxYq7pUE5c4lxhKXoZwBQ== X-Google-Smtp-Source: ABdhPJw4C1QO6SGuO1XGeekpJcbdpNnmdoqCX6g5HqEjse/xlq4shvpaq+kQrErxohP4VuoElKjQrAOmM15IICl0GCQ= X-Received: by 2002:a50:fe11:: with SMTP id f17mr2919405edt.88.1612960022961; Wed, 10 Feb 2021 04:27:02 -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> <20210210080311.GA3@paasikivi.fi.intel.com> In-Reply-To: <20210210080311.GA3@paasikivi.fi.intel.com> From: Bartosz Golaszewski Date: Wed, 10 Feb 2021 13:26:51 +0100 Message-ID: Subject: Re: [PATCH v10 7/7] at24: Support probing while off To: Sakari Ailus Cc: "Rafael J. Wysocki" , 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 Wed, Feb 10, 2021 at 9:41 AM Sakari Ailus wrote: > > On Tue, Feb 09, 2021 at 05:58:12PM +0100, Rafael J. Wysocki wrote: > > 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. > > Bartosz, would that work for you? > > I'd call the temporary variable in the at24 driver e.g. "full_power". > Yes, that works, go ahead and thank you. Bartosz