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=-16.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, 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 6EDB6C433E0 for ; Fri, 5 Feb 2021 20:10:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1885264FBA for ; Fri, 5 Feb 2021 20:10:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229864AbhBES1e (ORCPT ); Fri, 5 Feb 2021 13:27:34 -0500 Received: from mail.kernel.org ([198.145.29.99]:34770 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233706AbhBES1S (ORCPT ); Fri, 5 Feb 2021 13:27:18 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id EC17364FBA; Fri, 5 Feb 2021 20:09:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612555742; bh=beiP1QVTcTtnz/28je3Db2hFbKVGRBpJgYPrzRQ3FJY=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=HiHatxkiTqo19TZ7agC6KDqUsgXV67Li8ly2L0wqDAIgO/TnRxAG2RsEVs5oqP6c+ UaOzHqagc4QJeLih2kXFAEt5d7GhSEhvjlhL3gH10/QCgaTVU1AQai8Mn1NFjTiezP i1wgd9CTA84LgzCyhkwn5/kx2hr1+O0JvExsTupHij3anIzI/f4gsgHmz14r0nXCYL l0+YcKZuoB+EBsv5ijeTNTCycIDJJ3bqKmtNaMYKKxf/lWGat0JwJxc2r6hSYJ80aS IrqB6hXBSMagUQ342uqUdCGIfPNEt/aJJPrbGL+JfG1RPWW1Icry7tJhu+BlO9Wj7x cGUyryDyXIy7Q== Date: Fri, 5 Feb 2021 14:08:59 -0600 From: Bjorn Helgaas To: Guenter Roeck Cc: Yicong Yang , gregkh@linuxfoundation.org, jdelvare@suse.com, giometti@enneenne.com, abbotti@mev.co.uk, hsweeten@visionengravers.com, kw@linux.com, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, linux-hwmon@vger.kernel.org, devel@driverdev.osuosl.org, linux-kbuild@vger.kernel.org, masahiroy@kernel.org, michal.lkml@markovi.net, prime.zeng@huawei.com, linuxarm@openeuler.org Subject: Re: [PATCH 2/4] hwmon: Use subdir-ccflags-* to inherit debug flag Message-ID: <20210205200859.GA193526@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210205182832.GA186268@roeck-us.net> Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Fri, Feb 05, 2021 at 10:28:32AM -0800, Guenter Roeck wrote: > On Fri, Feb 05, 2021 at 05:44:13PM +0800, Yicong Yang wrote: > > From: Junhao He > > > > Use subdir-ccflags-* instead of ccflags-* to inherit the debug > > settings from Kconfig when traversing subdirectories. > > > > Suggested-by: Bjorn Helgaas > > Signed-off-by: Junhao He > > Signed-off-by: Yicong Yang > > What problem does this fix ? Maybe I am missing it, but I don't see > DEBUG being used in a subdirectory of drivers/hwmon. It's my fault for raising this question [1]. Yicong fixed a real problem in drivers/pci, where we are currently using ccflags-$(CONFIG_PCI_DEBUG) := -DDEBUG so CONFIG_PCI_DEBUG=y turns on debug in drivers/pci, but not in the subdirectories. That's surprising to users. So my question was whether we should default to using subdir-ccflags for -DDEBUG in general, and only use ccflags when we have subdirectories that have their own debug options, e.g., drivers/i2c/Makefile:ccflags-$(CONFIG_I2C_DEBUG_CORE) := -DDEBUG drivers/i2c/algos/Makefile:ccflags-$(CONFIG_I2C_DEBUG_ALGO) := -DDEBUG drivers/i2c/busses/Makefile:ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG drivers/i2c/muxes/Makefile:ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG I mentioned drivers/hwmon along with a few others that have subdirectories, do not have per-subdirectory debug options, and use ccflags. I didn't try to determine whether those subdirectories currently use -DDEBUG. In the case of drivers/hwmon, several drivers do use pr_debug(), and CONFIG_HWMON_DEBUG_CHIP=y turns those on. But if somebody were to add pr_debug() to drivers/hwmon/occ/common.c, for example, CONFIG_HWMON_DEBUG_CHIP=y would *not* turn it on. That sounds surprising to me, but if that's what you intend, that's totally fine. [1] https://lore.kernel.org/r/20210204161048.GA68790@bjorn-Precision-5520 > > --- > > drivers/hwmon/Makefile | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > > index 09a86c5..1c0c089 100644 > > --- a/drivers/hwmon/Makefile > > +++ b/drivers/hwmon/Makefile > > @@ -201,5 +201,5 @@ obj-$(CONFIG_SENSORS_XGENE) += xgene-hwmon.o > > obj-$(CONFIG_SENSORS_OCC) += occ/ > > obj-$(CONFIG_PMBUS) += pmbus/ > > > > -ccflags-$(CONFIG_HWMON_DEBUG_CHIP) := -DDEBUG > > +subdir-ccflags-$(CONFIG_HWMON_DEBUG_CHIP) := -DDEBUG > > > > -- > > 2.8.1 > >