Re: [PATCH 2/3] Thermal: core: Modify temp_crit_show() to use proper callback function.

From: Zhang Rui <rui.zhang@intel.com>
To: jonghwa3.lee@samsung.com
Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Eduardo Valentin <eduardo.valentin@ti.com>,
	Amit Dinel Kachhap <amit.kachhap@linaro.org>,
	MyungJoo Ham <myungjoo.ham@samsung.com>
Subject: Re: [PATCH 2/3] Thermal: core: Modify temp_crit_show() to use proper callback function.
Date: Thu, 23 May 2013 10:19:44 +0800	[thread overview]
Message-ID: <1369275584.2036.10.camel@rzhang1-mobl4> (raw)
In-Reply-To: <519ACE88.3090503@samsung.com>

On Tue, 2013-05-21 at 10:31 +0900, jonghwa3.lee@samsung.com wrote:
> On 2013년 05월 21일 00:57, Zhang, Rui wrote:
> 
> > 
> > 
> >> -----Original Message-----
> >> From: Jonghwa Lee [mailto:jonghwa3.lee@samsung.com]
> >> Sent: Saturday, May 18, 2013 5:51 PM
> >> To: linux-pm@vger.kernel.org
> >> Cc: linux-kernel@vger.kernel.org; Zhang, Rui; Eduardo Valentin; Amit
> >> Dinel Kachhap; Jonghwa Lee; MyungJoo Ham
> >> Subject: [PATCH 2/3] Thermal: core: Modify temp_crit_show() to use
> >> proper callback function.
> >> Importance: High
> >>
> >> This patch modifies temp_crit_show() which is used to create hwmon's
> >> sysfs node to use .get_crit_temp callback function of thermal zone
> >> device rather than .get_trip_temp.
> >>
> >> Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
> >> Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
> > 
> > The problem is that .get_crit_temp is optional for thermal drivers
> > that has a critical trip point.
> 
> 
> Actually, this is a interface for hwmon not generic thermal framework. And when
> we create this node through the thermal_add_hwmon_sysfs(), we've already checked
> whether call back function is available. So the problem won't happen.
> 
Oh, I see.

But back to my question, still take rcar driver for example,
it has a critical trip point but this is not shown in hwmon, which IMO
is still a problem.
So we should either make .get_crit_temp() mandatory for thermal drivers
with critical trip point or remove this callback and register hwmon
crit_temp interface via checking .get_trip_type().

thanks,
rui

> Thanks
> Jonghwa
> 
> > At least we do not have such kind of check in thermal core.
> > Take rcar_thermal driver for example,
> > It supports critical trip point but it does not have .get_crit_type.
> > 
> > So I'd like to see a fix in rcar thermal driver and thermal core
> > for this issue, together with this patch.
> > 
> > Thanks,
> > rui
> >> ---
> >>  drivers/thermal/thermal_core.c |    2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/thermal/thermal_core.c
> >> b/drivers/thermal/thermal_core.c index f753f48..ce4384a 100644
> >> --- a/drivers/thermal/thermal_core.c
> >> +++ b/drivers/thermal/thermal_core.c
> >> @@ -924,7 +924,7 @@ temp_crit_show(struct device *dev, struct
> >> device_attribute *attr,
> >>  	long temperature;
> >>  	int ret;
> >>
> >> -	ret = tz->ops->get_trip_temp(tz, 0, &temperature);
> >> +	ret = tz->ops->get_crit_temp(tz, &temperature);
> >>  	if (ret)
> >>  		return ret;
> >>
> >> --
> >> 1.7.9.5
> > 
> > 
> 
> 