From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Frank Wunderlich <frank-w@public-files.de>
Cc: Frank Wunderlich <linux@fw-web.de>,
linux-pm@vger.kernel.org, "Rafael J. Wysocki" <rafael@kernel.org>,
Viresh Kumar <vireshk@kernel.org>, Nishanth Menon <nm@ti.com>,
Stephen Boyd <sboyd@kernel.org>,
linux-kernel@vger.kernel.org
Subject: Re: [RFC v1] opp: add config option for debug
Date: Thu, 5 May 2022 19:57:37 +0200 [thread overview]
Message-ID: <YnQQEZ7eoa/ZbmEj@kroah.com> (raw)
In-Reply-To: <E08A9747-2F96-42A7-A427-0E00D4075CF0@public-files.de>
On Thu, May 05, 2022 at 07:50:56PM +0200, Frank Wunderlich wrote:
> Hi,
>
> Am 4. Mai 2022 20:24:00 MESZ schrieb Greg Kroah-Hartman <gregkh@linuxfoundation.org>:
> >On Wed, May 04, 2022 at 07:48:23PM +0200, Frank Wunderlich wrote:
> >> From: Frank Wunderlich <frank-w@public-files.de>
> >>
> >> Currently OPP debug is enabled by DEBUG_DRIVER option. This is
> >generic
> >> driver debug and opp floods serial console. This is annoying if opp
> >is
> >> not needed so give it an additional config-key.
> >>
> >> Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
> >> ---
> >> drivers/base/Kconfig | 1 +
> >> drivers/opp/Kconfig | 7 +++++++
> >> drivers/opp/Makefile | 2 +-
> >> 3 files changed, 9 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
> >> index 6f04b831a5c0..8ae826c95d5f 100644
> >> --- a/drivers/base/Kconfig
> >> +++ b/drivers/base/Kconfig
> >> @@ -130,6 +130,7 @@ config DEV_COREDUMP
> >> config DEBUG_DRIVER
> >> bool "Driver Core verbose debug messages"
> >> depends on DEBUG_KERNEL
> >> + imply DEBUG_OPP
> >
> >This should not be needed, otherwise we would have to do that for all
> >random driver subsystem in the kernel.
>
> Have added this to have same behaviour if anyone sets DEBUG_DRIVER via defconfig. Else this is disabled by default.
>
> >> help
> >> Say Y here if you want the Driver core to produce a bunch of
> >> debug messages to the system log. Select this if you are having a
> >> diff --git a/drivers/opp/Kconfig b/drivers/opp/Kconfig
> >> index e8ce47b32735..6a2d2c6c1143 100644
> >> --- a/drivers/opp/Kconfig
> >> +++ b/drivers/opp/Kconfig
> >> @@ -12,3 +12,10 @@ config PM_OPP
> >> representing individual voltage domains and provides SOC
> >> implementations a ready to use framework to manage OPPs.
> >> For more information, read <file:Documentation/power/opp.rst>
> >> +
> >> +menu "Operating Performance Points (OPP)"
> >> +config DEBUG_OPP
> >> + bool "Debug Operating Performance Points"
> >> + help
> >> + enable opp debugging
> >> +endmenu
> >> diff --git a/drivers/opp/Makefile b/drivers/opp/Makefile
> >> index f65ed5985bb4..2589915eef95 100644
> >> --- a/drivers/opp/Makefile
> >> +++ b/drivers/opp/Makefile
> >> @@ -1,5 +1,5 @@
> >> # SPDX-License-Identifier: GPL-2.0-only
> >> -ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG
> >> +ccflags-$(CONFIG_DEBUG_OPP) := -DDEBUG
> >
> >This feels wrong, you shouldn't need a -DDEBUG for anything if all is
> >going correctly. Why is opp so odd this way? Just use the normal
> >dev_dbg() macros and all will be fine, nothing special should be needed
> >at all.
>
> I have looked more into it,just wanted to get driver debug (probing/binding) and dev_dbg messages without the opp spam (floods serial console).
>
> >And don't use a config option for it either, no one will turn it on, it
> >needs to "just work" for all systems.
>
> Config option is to enable if needed and not via driver-debug.
Please do not do that, you should never need subsystem/driver Kconfig
options like this. Distros will never enable them and you can't ask a
user to rebuild their kernel easily. Just rely on the same
infrastructure like all other subsystems do please.
thanks,
greg k-h
next prev parent reply other threads:[~2022-05-05 17:57 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-04 17:48 [RFC v1] opp: add config option for debug Frank Wunderlich
2022-05-04 18:24 ` Greg Kroah-Hartman
2022-05-05 17:50 ` Frank Wunderlich
2022-05-05 17:57 ` Greg Kroah-Hartman [this message]
2022-05-05 5:58 ` Viresh Kumar
2022-05-05 15:54 ` Aw: " Frank Wunderlich
2022-05-05 17:38 ` Greg Kroah-Hartman
2022-05-06 4:06 ` Viresh Kumar
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