Message-ID: <1424468908.24292.10.camel@x220>
Subject: Re: [PATCH v2 04/18] clocksource: Add ARM System timer driver
From: Paul Bolle <pebolle@tiscali.nl>
To: Uwe =?ISO-8859-1?Q?Kleine-K=F6nig?= 
	<u.kleine-koenig@pengutronix.de>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>, afaerber@suse.de,
        geert@linux-m68k.org, Rob Herring <robh+dt@kernel.org>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Jonathan Corbet <corbet@lwn.net>, Pawel Moll <pawel.moll@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Ian Campbell <ijc+devicetree@hellion.org.uk>,
        Kumar Gala <galak@codeaurora.org>,
        Russell King <linux@arm.linux.org.uk>,
        Daniel Lezcano <daniel.lezcano@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Linus Walleij <linus.walleij@linaro.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jiri Slaby <jslaby@suse.cz>, Arnd Bergmann <arnd@arndb.de>,
        Andrew Morton <akpm@linux-foundation.org>,
        "David S. Miller" <davem@davemloft.net>,
        Mauro Carvalho Chehab <mchehab@osg.samsung.com>,
        Joe Perches <joe@perches.com>, Antti Palosaari <crope@iki.fi>,
        Tejun Heo <tj@kernel.org>, Will Deacon <will.deacon@arm.com>,
        Nikolay Borisov <Nikolay.Borisov@arm.com>,
        Rusty Russell <rusty@rustcorp.com.au>,
        Kees Cook <keescook@chromium.org>, Michal Marek <mmarek@suse.cz>,
        linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
        linux-gpio@vger.kernel.org, linux-serial@vger.kernel.org,
        linux-arch@vger.kernel.org, linux-api@vger.kernel.org
Date: Fri, 20 Feb 2015 22:48:28 +0100
In-Reply-To: <20150220195437.GT19388@pengutronix.de>
References: <1424455277-29983-1-git-send-email-mcoquelin.stm32@gmail.com>
	 <1424455277-29983-5-git-send-email-mcoquelin.stm32@gmail.com>
	 <20150220195437.GT19388@pengutronix.de>
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On Fri, 2015-02-20 at 20:54 +0100, Uwe Kleine-König wrote:
> On Fri, Feb 20, 2015 at 07:01:03PM +0100, Maxime Coquelin wrote:
> > This patch adds clocksource support for ARMv7-M's System timer,
> > also known as SysTick.
> > 
> > Signed-off-by: Maxime Coquelin <mcoquelin.stm32@gmail.com>
> > ---
> >  drivers/clocksource/Kconfig          |  7 ++++
> >  drivers/clocksource/Makefile         |  1 +
> >  drivers/clocksource/armv7m_systick.c | 78 ++++++++++++++++++++++++++++++++++++
> >  3 files changed, 86 insertions(+)
> >  create mode 100644 drivers/clocksource/armv7m_systick.c
> > 
> > diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
> > index fc01ec2..fb6011e 100644
> > --- a/drivers/clocksource/Kconfig
> > +++ b/drivers/clocksource/Kconfig
> > @@ -124,6 +124,13 @@ config CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK
> >  	help
> >  	 Use ARM global timer clock source as sched_clock
> >  
> > +config ARMV7M_SYSTICK
> > +	bool
> I assume this symbol is enabled later in the series.

Yes, I noticed it was selected in 14/18 ("ARM: Add STM32 family
machine").

> Would it make sense
> to allow enabing the symbol for compile test coverage?
> 
> > +	select CLKSRC_OF if OF
> What happens if ARMV7M_SYSTICK=y but OF=n? Doesn't the driver fail to
> compile?
> 
> > +	select CLKSRC_MMIO
> > +	help
> > +	  This options enables support for the ARMv7M system timer unit
> the right spelling is ARMv7-M.

This Kconfig entry has no prompt, so no one is going to see this text
during make *config. Perhaps this should be made a comment. In that case
the right spelling should still be used.

Thanks,


Paul Bolle

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