Re: [PATCH] thermal: power_allocator: Use temperature reading from tz

[Kapileshwar Singh <kapileshwar.singh@arm.com>]

If there are no objections to this patch, can this be picked up for the 
next RC?

Regards,
KP

On 15/10/15 11:58, Javi Merino wrote:
> On Wed, Oct 14, 2015 at 05:28:49AM +0000, Chen, Yu C wrote:
>>> -----Original Message-----
>>> From: linux-pm-owner@vger.kernel.org [mailto:linux-pm-
>>> owner@vger.kernel.org] On Behalf Of Kapileshwar Singh
>>> Sent: Tuesday, October 13, 2015 7:30 PM
>>> To: linux-pm@vger.kernel.org
>>> Cc: Kapileshwar Singh; Javi Merino; Eduardo Valentin; Daniel Kurtz; Zhang, Rui;
>>> Dmitry Torokhov; Sascha Hauer; Andrea Arcangeli
>>> Subject: [PATCH] thermal: power_allocator: Use temperature reading from
>>> tz
>>>
>>> All thermal governors use the temperature value stored in struct
>>> thermal_zone_device.
>>>
>>>     thermal_zone_device->temperature
>>>
>>> power_allocator governor should not deviate from this and use the same.
>>>
>> Just my 2 cents:
>> I wonder if tz->temperature would vary during power_allocator_throttle?
>> because we don't have tz->lock to protect here.
> True, tz->temperature could vary but I don't think it's problematic.
> tz->temperature changing would mean that it doesn't pass this condition:
>
> 	if (!ret && (tz->temperature < switch_on_temp)) {
>
> and then, the temperature changes to a value below switch_on_temp
> before the call to allocate_power().  allocate_power() would still
> work and make an appropriate decision.
>
> All calls inside allocate_power() are protected by tz->lock, so the
> temperature used in pid_controller() is the same as the one reported
> to ftrace.
>
> In summary, I don't think it has any impact on functionality.  Thanks
> a lot for the review,
> Javi
>