On 10/30/2013 03:40 PM, Tomasz Figa wrote:
Hi Daniel,
On Wednesday 30 of October 2013 14:43:51 Daniel Lezcano wrote:
On 10/25/2013 03:23 PM, Daniel Lezcano wrote:
[ ... ]
Won't it be worth to add a new WFI_SLEEP state to the cpuidle driver
?
I don't think so. How a suspend-to-RAM specific thing like WFI_SLEEP
could
be relevant to a cpuidle driver? (Unless there are some plans to
consolidate STR with cpuidle that I haven't heard about...)
I finally found a documentation for the s3c6410x and the description
of
the different modes. Indeed, the sleep mode is not adequate for a
cpuidle state. What about the 'stop' and 'deep stop' state ?
Hi Thomas,
just a reminder about the question above, so I can go ahead: fix what
you pointed out or remove the driver directly.
You mentionned in the previous email the STOP is not usful because it
can be controlled by manually outside of the cpuidle driver. But I see
in the documentation, the stop states power gates the cpu and deep-stop
stops the regulator.
STOP clock-gates the CPU and DEEP-STOP power-gates it by stopping the
regulator.
There are some interesting aspects of those modes, like memory self-
refresh, PLL power-off and system-wide down clocking, but I believe they
are too tricky to handle (coupling with device PM, stopped timers) and
with too little possible power saving to justify the effort of adding
support for them.
In the end, I haven't seen support for them implemented even in strange
vendor kernels used even on production devices, like Android phones.
If these states have to been added later, still it worth to remove the
driver ?
I don't think that anybody is even going to add support for them and by
anybody I should probably mean myself, since I'm currently the only person
actively adding new code for this platform, as a part of my hobby.
Ok, I will kill the driver then.
Thanks
-- Daniel
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