On 5/31/2018 11:47 AM, MyungJoo Ham wrote:
Currently, DEVFREQ reevaluates the device state periodically and/or
based on the OPP list changes. Private API has to be exposed to allow
the device driver to alert/notify the governor to reevaluate when a new
set of data is available. This makes the governor more coupled to a
particular device driver. We can improve here by exposing a DEVFREQ API
to allow the device drivers to send generic alerts to the governor.

Signed-off-by: Akhil P Oommen <akhi...@codeaurora.org>
---
  drivers/devfreq/devfreq.c  | 21 +++++++++++++++++++++
  drivers/devfreq/governor.h |  1 +
  include/linux/devfreq.h    |  5 +++++
  3 files changed, 27 insertions(+)

Hello Akhil,

It appears that this will have the same effect with
"[PATCH 08/11] PM / devfreq: Make update_devfreq() public" from Matthias 
Kaehlcke, doesn't it?


Cheers,
MyungJoo

Hi MyngJoo,

The patch you mentioned is a step in the right direction. But this patch allows: 1. the governor to decide whether to reevaluate or not. I feel it would be a better architecture (better Separation of Concern) if that decision is left to the governor alone. 2. the devices to share multiple types of alerts. A governor may use these alerts for internal bookkeeping/algorithm and decide to reevaluate policy when it is necessary. Since we are opening up a new devfreq API for devices, isn't it better to go for a generic one?

Regards,
Akhil.

Reply via email to