lkml.org 
[lkml]   [2018]   [May]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [RFC PATCH 00/10] Add persistent clock support
Hi Daniel,

On 15 May 2018 at 18:27, Daniel Lezcano <daniel.lezcano@linaro.org> wrote:
> On Mon, May 14, 2018 at 04:55:26PM +0800, Baolin Wang wrote:
>> Hi,
>>
>> We will meet below issues when compensating the suspend time for the timekeeping.
>>
>> 1. We have too many different ways of dealing with persistent timekeeping
>> across architectures, so it is hard for one driver to compatable with different
>> architectures.
>>
>> 2. On some platforms (such as Spreadtrum platform), we registered the high
>> resolution timer as one clocksource to update the OS time, but the high
>> resolution timer will be stopped in suspend state. So we use another one
>> always-on timer (but low resolution) to calculate the suspend time to
>> compensate the OS time. Though we can register the always-on timer as one
>> clocksource, we need re-calculate the mult/shift with one larger conversion
>> range to calculate the suspend time and need update the clock in case of
>> running over the always-on timer.
>
> First, can you elaborate what you mean by 'suspend state' ? On which power

What I mean is the high resolution timer will be stopped when the
system goes into suspend state.

> domain the clocksource belongs to?

On Spreadtrum platform, It belongs to one power domain named
"APCPU_TOP", that will be power down when the system goes into suspend
state.

--
Baolin.wang
Best Regards

\
 
 \ /
  Last update: 2018-05-16 04:20    [W:0.120 / U:1.388 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site