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 2524BC00140 for ; Mon, 8 Aug 2022 10:06:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242354AbiHHKGp (ORCPT ); Mon, 8 Aug 2022 06:06:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242258AbiHHKGl (ORCPT ); Mon, 8 Aug 2022 06:06:41 -0400 Received: from aposti.net (aposti.net [89.234.176.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 067B611808 for ; Mon, 8 Aug 2022 03:06:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=crapouillou.net; s=mail; t=1659953197; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=AwLi/sxUWbQ2u8h1M+uWOgbjCN8M4cM8EmRaHGzr1aw=; b=4Fj2elb/irp4DtXDZKVbLFKAf9tQJvWN3VXmNprQjjbK/g3eN9EJe4IUnjuyE0Zhe1clzo UN0GK6wWjGgU7iOBLZajrjE0fHd2bcKwYug3FrVM5/y0LTFR3puyJK+MSke5gTdIKF1l6k VpgKaH3SIhFVGgujlP+kz33S17JaxI0= Date: Mon, 08 Aug 2022 12:06:29 +0200 From: Paul Cercueil Subject: Re: [PATCH 20/28] mfd: arizona: Remove #ifdef guards for PM related functions To: Richard Fitzgerald Cc: Lee Jones , linux-kernel@vger.kernel.org, patches@opensource.cirrus.com Message-Id: In-Reply-To: <94394206-a018-27b0-5a21-97976fc4a3bc@opensource.cirrus.com> References: <20220807145247.46107-1-paul@crapouillou.net> <20220807145247.46107-21-paul@crapouillou.net> <94394206-a018-27b0-5a21-97976fc4a3bc@opensource.cirrus.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Richard, Le lun., ao=FBt 8 2022 at 10:53:54 +0100, Richard Fitzgerald=20 a =E9crit : > On 07/08/2022 15:52, Paul Cercueil wrote: >> Only export the arizona_pm_ops if CONFIG_PM is set, but leave the >> suspend/resume functions (and related code) outside #ifdef guards. >>=20 >> If CONFIG_PM is not set, the arizona_pm_ops will be defined as >> "static __maybe_unused", and the structure plus all the callbacks=20 >> will >> be automatically dropped by the compiler. >>=20 >> The advantage is then that these functions are now always compiled >> independently of any Kconfig option, and thanks to that bugs and >> regressions are easier to catch. >>=20 >> Signed-off-by: Paul Cercueil >> Cc: patches@opensource.cirrus.com >> --- >> drivers/mfd/arizona-core.c | 21 +++++++++++---------- >> drivers/mfd/arizona-i2c.c | 2 +- >> drivers/mfd/arizona-spi.c | 2 +- >> 3 files changed, 13 insertions(+), 12 deletions(-) >>=20 >> diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c >> index cbf1dd90b70d..c1acc9521f83 100644 >> --- a/drivers/mfd/arizona-core.c >> +++ b/drivers/mfd/arizona-core.c >> @@ -480,7 +480,6 @@ static int wm5102_clear_write_sequencer(struct=20 >> arizona *arizona) >> return 0; >> } >> =7F-#ifdef CONFIG_PM >> static int arizona_isolate_dcvdd(struct arizona *arizona) >=20 > __maybe_unused? No need. The symbols are always referenced. >> { >> int ret; >> @@ -742,9 +741,7 @@ static int arizona_runtime_suspend(struct device=20 >> *dev) >=20 > __maybe_unused? >=20 >> =7F return 0; >> } >> -#endif >> =7F-#ifdef CONFIG_PM_SLEEP >> static int arizona_suspend(struct device *dev) >=20 > __maybe_unused? >=20 >> { >> struct arizona *arizona =3D dev_get_drvdata(dev); >> @@ -784,17 +781,21 @@ static int arizona_resume(struct device *dev) >=20 > __maybe_unused? >=20 >> =7F return 0; >> } >> -#endif >> =7F+#ifndef CONFIG_PM >> +static __maybe_unused >> +#endif >=20 > No need to ifdef a __maybe_unused. Yes, it is needed, because the symbol is conditionally exported. If=20 !CONFIG_PM, we want the compiler to discard the dev_pm_ops and all the=20 callbacks, hence the "static __maybe_unused". That's the same trick=20 used in _EXPORT_DEV_PM_OPS(). (note that this patch is broken as it does not change the struct name,=20 in the !PM case, which causes conflicts with the .h. I'll fix in v2) >> const struct dev_pm_ops arizona_pm_ops =3D { >> - SET_RUNTIME_PM_OPS(arizona_runtime_suspend, >> - arizona_runtime_resume, >> - NULL) >> - SET_SYSTEM_SLEEP_PM_OPS(arizona_suspend, arizona_resume) >> - SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(arizona_suspend_noirq, >> - arizona_resume_noirq) >> + RUNTIME_PM_OPS(arizona_runtime_suspend, >> + arizona_runtime_resume, >> + NULL) >> + SYSTEM_SLEEP_PM_OPS(arizona_suspend, arizona_resume) >> + NOIRQ_SYSTEM_SLEEP_PM_OPS(arizona_suspend_noirq, >> + arizona_resume_noirq) >> }; >> +#ifdef CONFIG_PM >> EXPORT_SYMBOL_GPL(arizona_pm_ops); >> +#endif >=20 > This ifdeffing is ugly. Why must the structure only be exported if > CONFIG_PM is set? So that all the PM code is garbage-collected by the compiler if=20 !CONFIG_PM. Ideally I would use something like EXPORT_SIMPLE_DEV_PM_OPS() which=20 would make the patch much cleaner, but it doesn't support noirq=20 callbacks - and that's why I suggested in the cover letter that maybe a=20 new PM macro can be added if this patch is deemed too messy. Cheers, -Paul >> =7F #ifdef CONFIG_OF >> static int arizona_of_get_core_pdata(struct arizona *arizona) >> diff --git a/drivers/mfd/arizona-i2c.c b/drivers/mfd/arizona-i2c.c >> index 6d83e6b9a692..8799d9183bee 100644 >> --- a/drivers/mfd/arizona-i2c.c >> +++ b/drivers/mfd/arizona-i2c.c >> @@ -119,7 +119,7 @@ static const struct of_device_id=20 >> arizona_i2c_of_match[] =3D { >> static struct i2c_driver arizona_i2c_driver =3D { >> .driver =3D { >> .name =3D "arizona", >> - .pm =3D &arizona_pm_ops, >> + .pm =3D pm_ptr(&arizona_pm_ops), >> .of_match_table =3D of_match_ptr(arizona_i2c_of_match), >> }, >> .probe =3D arizona_i2c_probe, >> diff --git a/drivers/mfd/arizona-spi.c b/drivers/mfd/arizona-spi.c >> index 941b0267d09d..da05b966d48c 100644 >> --- a/drivers/mfd/arizona-spi.c >> +++ b/drivers/mfd/arizona-spi.c >> @@ -282,7 +282,7 @@ static const struct of_device_id=20 >> arizona_spi_of_match[] =3D { >> static struct spi_driver arizona_spi_driver =3D { >> .driver =3D { >> .name =3D "arizona", >> - .pm =3D &arizona_pm_ops, >> + .pm =3D pm_ptr(&arizona_pm_ops), >> .of_match_table =3D of_match_ptr(arizona_spi_of_match), >> .acpi_match_table =3D ACPI_PTR(arizona_acpi_match), >> },