Re: [PATCH] thermal: consistently use int for temperatures

From: Sascha Hauer <s.hauer@pengutronix.de>
To: Punit Agrawal <punit.agrawal@arm.com>
Cc: linux-pm@vger.kernel.org, Zhang Rui <rui.zhang@intel.com>,
	Eduardo Valentin <edubezval@gmail.com>,
	linux-kernel@vger.kernel.org, Jean Delvare <jdelvare@suse.de>,
	Peter Feuerer <peter@piie.net>, Heiko Stuebner <heiko@sntech.de>,
	Lukasz Majewski <l.majewski@samsung.com>,
	Stephen Warren <swarren@wwwdotorg.org>,
	Thierry Reding <thierry.reding@gmail.com>,
	linux-acpi@vger.kernel.org, platform-driver-x86@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org,
	linux-samsung-soc@vger.kernel.org,
	Guenter Roeck <linux@roeck-us.net>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Maxime Ripard <maxime.ripard@free-electrons.com>,
	Darren Hart <dvhart@infradead.org>,
	lm-sensors@lm-sensors.org
Subject: Re: [PATCH] thermal: consistently use int for temperatures
Date: Tue, 21 Jul 2015 09:31:11 +0200	[thread overview]
Message-ID: <20150721073111.GH5161@pengutronix.de> (raw)
In-Reply-To: <9hhd1zrc9yb.fsf@e105922-lin.cambridge.arm.com>

Hi Punit,

On Fri, Jul 17, 2015 at 12:14:36PM +0100, Punit Agrawal wrote:
> Hi Sascha,
> 
> Sascha Hauer <s.hauer@pengutronix.de> writes:
> 
> > The thermal code uses int, long and unsigned long for temperatures
> > in different places.
> >
> > Using an unsigned type limits the thermal framework to positive
> > temperatures without need. Also several drivers currently will report
> > temperatures near UINT_MAX for temperatures below 0°C. This will probably
> > immediately shut the machine down due to overtemperature if started below
> > 0°C.
> >
> > 'long' is 64bit on several architectures. This is not needed since INT_MAX °mC
> > is above the melting point of all known materials.
> >
> > Consistently use a plain 'int' for temperatures throughout the thermal code and
> > the drivers. This only changes the places in the drivers where the temperature
> > is passed around as pointer, when drivers internally use another type this is
> > not changed.
> >
> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> 
> Thanks for moving over the thermal sub-system in Linux to consistently
> use a single type.
> 
> In your patch, you missed migrating over power_allocator governor and
> it's associated trace events. It got merged for v4.2.
> 
> Could you incorporate something like below in your next version?

It seems I have changed drivers/thermal/power_allocator.c but missed
include/trace/events/thermal_power_allocator.h. Please check out the v2
patch I just sent.

Sascha

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