Re: [PATCH 2/3] thermal: Add Mediatek thermal controller support

From: Matthias Brugger
Date: Wed Feb 17 2016 - 12:06:08 EST




On 15/02/16 03:14, Daniel Kurtz wrote:
On Mon, Feb 15, 2016 at 10:11 AM, Daniel Kurtz <djkurtz@xxxxxxxxxxxx> wrote:
Hi Eduardo, Sascha,

On Mon, Feb 1, 2016 at 10:54 AM, Eddie Huang <eddie.huang@xxxxxxxxxxxx> wrote:

On Tue, 2016-01-19 at 15:29 +0800, Sascha Hauer wrote:
Eduardo,

On Mon, Jan 04, 2016 at 03:19:40PM +0100, Sascha Hauer wrote:
Hi Eduardo,


That should remove the policy of computing the maximum from this driver.
Please have a look on the work being done [1] to add grouping and
aggregation of thermal zones. With that in place, you should be a matter
of configuring the grouping and selecting max as the aggregation function,
from the thermal core, instead in the driver. Which should give the
system engineer, more flexibility to compose whatever policy based on
the exposed sensors.

I think the aggregation of thermal zones is quite useful when it comes
to putting different chips together to a system. I am not so sure how
useful it is to expose different thermal zones of a single SoC to the
device tree.
Currently the only control knob we have is the CPU frequency. When any
of the sensors on the SoC gets too hot then the only thing we can do is
to decrease the CPU frequency. This does not leave much space for
configuration in the device tree.
What I need to be able is to attach multiple sensors to one thermal
zone. The aggregation patch series only partly solves that and I think
is inconsistent, but I commented on the series directly.

Any input on this? I really like to get this driver upstream as it is
currently blocking other Mediatek drivers.


Hi Eduardo,

Do you have any comment about Sascha's response ? We really hope get
your comment since Mediatek thermal driver already reviewed in public
over half years, and we have other patches [0] [1] depend on thermal
driver.

[0]:
http://lists.infradead.org/pipermail/linux-arm-kernel/2015-December/394084.html
[1]:
http://lists.infradead.org/pipermail/linux-arm-kernel/2016-January/401055.html

Friendly ping on the Mediatek thermal driver.
The "EFUSE" dependency has now landed in v4.5-rc4.

Actually, it landed in char-misc-next, not v4.5-rc4.

So, AFAICT, the only thing left that may be blocking landing Mediatek
thermal driver is resolution of this discussion about thermal zones.
Can we kindly resolve this soon so we have a chance to land it in v4.6.



I think the problem is, that Eduardo wants to see the hierachical thermal zones being used. But there is still a discussion ongoing [1].

[1] https://patchwork.kernel.org/patch/7699971/