2009/3/23 Li Yang-R58472 [off-list ref]

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-----Original Message-----
From: Wood Scott-B07421
Sent: Friday, March 20, 2009 10:42 PM
To: Li Yang-R58472
Cc: Soohyung Cho; linuxppc-dev@ozlabs.org
Subject: Re: suspend-to-mem on the mpc8349e-mitx-gp?

Li Yang-R58472 wrote:

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However, the code should treat "mem" as "standby" on chips

that don't

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support deep sleep.  What does the device tree

Well, shouldn't the valid() callback reject unsupported

states instead

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of covering up?

I don't think so, in this case.  The user is not asking for
"sleep" or deep sleep"; they are asking for a power state
that meets the definition of "standby" (which sleep does) or
which meets the definition of "mem"
(which both sleep and deep sleep do).  When the user asks for
"mem", we provide the lowest power mode that qualifies.

In my understanding, "mem" which is suspend-to-ram means all CPU states and
registers are kept in memory and the CPU is completely off during
suspension.  I don't think the sleep mode of 8349 qualifies, does it?

- Leo

I also agree to Leo.
It can be confusing, if "mem" means both sleep and deep sleep.
It would be better not to show "mem", if 8349 don't have deep sleep mode.

- Soohyung