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 AD83DEB64DA for ; Tue, 18 Jul 2023 13:48:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229766AbjGRNsy (ORCPT ); Tue, 18 Jul 2023 09:48:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45430 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230198AbjGRNse (ORCPT ); Tue, 18 Jul 2023 09:48:34 -0400 Received: from aposti.net (aposti.net [89.234.176.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A1F948F; Tue, 18 Jul 2023 06:48:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=crapouillou.net; s=mail; t=1689688111; h=from:from: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=KihHBXzQ5YscflwfpTqH3zKYKGvYlYBWepP0Q5n+rtU=; b=UNdTDGqa0OtoBQaI2l3ghDjFxpMFaBpM9l/Ykjhq7diTw50XCdiPIhpvvlr1SxESWzw6G6 eKk/Z+BPbTVo1rMmomxkPZJtkaxvHfHzhBb4ZpemqpEKMHvEKSuxYE4JJxjQW1a4PGMsWH QtcsjXWqbehZKL69FjxVnejBKvKxNTE= Message-ID: Subject: Re: [PATCH v2 10/10] pinctrl: tegra: Switch to use DEFINE_NOIRQ_DEV_PM_OPS() helper From: Paul Cercueil To: Thierry Reding Cc: Andy Shevchenko , Mika Westerberg , Linus Walleij , Balsam CHIHI , Claudiu Beznea , Geert Uytterhoeven , Wolfram Sang , linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-renesas-soc@vger.kernel.org, linux-tegra@vger.kernel.org, linux-pm@vger.kernel.org, Andy Shevchenko , Sean Wang , Matthias Brugger , AngeloGioacchino Del Regno , Andrew Lunn , Gregory Clement , Sebastian Hesselbarth , Ludovic Desroches , Nicolas Ferre , Alexandre Belloni , Jonathan Hunter , "Rafael J. Wysocki" , Len Brown , Pavel Machek Date: Tue, 18 Jul 2023 15:48:27 +0200 In-Reply-To: References: <20230717172821.62827-1-andriy.shevchenko@linux.intel.com> <20230717172821.62827-11-andriy.shevchenko@linux.intel.com> <13f7153786cfcdc3c6185a3a674686f7fbf480dc.camel@crapouillou.net> <5e4b5bc23f3edb3ed30cb465420a51ffceceb53d.camel@crapouillou.net> <8f32cb8377808a073b043e0adf3ccf5ae5a84c92.camel@crapouillou.net> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Thierry, Le mardi 18 juillet 2023 =C3=A0 15:20 +0200, Thierry Reding a =C3=A9crit=C2= =A0: > On Tue, Jul 18, 2023 at 01:55:05PM +0200, Paul Cercueil wrote: > > Le mardi 18 juillet 2023 =C3=A0 13:41 +0200, Thierry Reding a =C3=A9cri= t=C2=A0: > > > On Tue, Jul 18, 2023 at 10:42:47AM +0200, Paul Cercueil wrote: > > > > Hi Thierry, > > > >=20 > > > > Le mardi 18 juillet 2023 =C3=A0 09:45 +0200, Thierry Reding a > > > > =C3=A9crit=C2=A0: > > > > > On Mon, Jul 17, 2023 at 09:14:12PM +0200, Paul Cercueil > > > > > wrote: > > > > > > Hi Andy, > > > > > >=20 > > > > > > Le lundi 17 juillet 2023 =C3=A0 20:28 +0300, Andy Shevchenko a > > > > > > =C3=A9crit=C2=A0: > > > > > > > Since pm.h provides a helper for system no-IRQ PM > > > > > > > callbacks, > > > > > > > switch the driver to use it instead of open coded > > > > > > > variant. > > > > > > >=20 > > > > > > > Signed-off-by: Andy Shevchenko > > > > > > > > > > > > > > --- > > > > > > > =C2=A0drivers/pinctrl/tegra/pinctrl-tegra.c | 5 +---- > > > > > > > =C2=A01 file changed, 1 insertion(+), 4 deletions(-) > > > > > > >=20 > > > > > > > diff --git a/drivers/pinctrl/tegra/pinctrl-tegra.c > > > > > > > b/drivers/pinctrl/tegra/pinctrl-tegra.c > > > > > > > index 4547cf66d03b..734c71ef005b 100644 > > > > > > > --- a/drivers/pinctrl/tegra/pinctrl-tegra.c > > > > > > > +++ b/drivers/pinctrl/tegra/pinctrl-tegra.c > > > > > > > @@ -747,10 +747,7 @@ static int > > > > > > > tegra_pinctrl_resume(struct > > > > > > > device > > > > > > > *dev) > > > > > > > =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0return 0; > > > > > > > =C2=A0} > > > > > > > =C2=A0 > > > > > > > -const struct dev_pm_ops tegra_pinctrl_pm =3D { > > > > > > > -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0.suspend_noirq =3D= &tegra_pinctrl_suspend, > > > > > > > -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0.resume_noirq =3D = &tegra_pinctrl_resume > > > > > > > -}; > > > > > > > +DEFINE_NOIRQ_DEV_PM_OPS(tegra_pinctrl_pm, > > > > > > > tegra_pinctrl_suspend, > > > > > > > tegra_pinctrl_resume); > > > > > > > =C2=A0 > > > > > > > =C2=A0static bool tegra_pinctrl_gpio_node_has_range(struct > > > > > > > tegra_pmx > > > > > > > *pmx) > > > > > > > =C2=A0{ > > > > > >=20 > > > > > > Another driver where using EXPORT_GPL_DEV_PM_OPS() would > > > > > > make > > > > > > more > > > > > > sense. > > > > >=20 > > > > > We don't currently export these PM ops because none of the > > > > > Tegra > > > > > pinctrl > > > > > drivers can be built as a module. > > > >=20 > > > > This doesn't change anything. You'd want to use > > > > EXPORT_GPL_DEV_PM_OPS > > > > (or better, the namespaced version) so that the PM ops can be > > > > defined > > > > in one file and referenced in another, while still having them > > > > garbage- > > > > collected when CONFIG_PM is disabled. > > >=20 > > > Looking at the definition of EXPORT_GPL_DEV_PM_OPS(), it will > > > cause > > > an > > > EXPORT_SYMBOL_GPL() to be added. So there very well is a change. > > > And > > > it's a completely bogus change because no module is ever going to > > > use > > > that symbol. If we were to ever support building the pinctrl > > > driver > > > as > > > a module, then this would perhaps make sense, but we don't. > >=20 > > In this particular case the EXPORT_SYMBOL_GPL() isn't really > > important, > > the rest of EXPORT_GPL_DEV_PM_OPS() is. > >=20 > > I don't think having a symbol exported it is a big deal, TBH, if > > you > > use the namespaced version. If you really don't want that, we need > > a > > version of EXPORT_GPL_DEV_PM_OPS() that doesn't export the symbol. >=20 > I do think it's a big deal to export a symbol if there's no reason to > do > so. >=20 > And please, can we stop adding these macros for every possible > scenario? Yes, as you can read from my other responses, I am not really keen on having a multiplication of these macros. > Maybe I'm just getting old, but I find it increasingly difficult to > understand what all of these are supposed to be. I get that people > want > to get rid of boilerplate, but I think we need to more carefully > balance > boilerplate vs. simplicity. The EXPORT_GPL_DEV_PM_OPS() macro does more than get rid of boilerplate, it gets rid of dead code. If we take this driver as an example, before the patch the "tegra_pinctrl_pm" struct, as well as the "tegra_pinctrl_suspend" and "tegra_pinctrl_resume" functions were always compiled in, even if CONFIG_PM_SLEEP is disabled in the config. The status-quo before the introduction of the new PM macros was to just wrap the dev_pm_ops struct + callbacks with a #ifdef CONFIG_PM_SLEEP. This was pretty bad as the code was then conditionally compiled. With the new PM macros this code is always compiled, independently of any Kconfig option; and thanks to that, bugs and regressions are subsequently easier to catch. Cheers, -Paul > I'm seeing the same thing with stuff like those mass conversions to > atrocities like devm_platform_ioremap_resource() and > devm_platform_get_and_ioremap_resource(). There's so much churn > involved > in getting those merged for usually saving a single line of code. And > it's not even mass conversions, but people tend to send these as one > patch per driver, which doesn't exactly help (except perhaps for > patch > statistics). >=20 > Thierry