[PATCH/RFC 3/6] drivers: firmware: psci: Implement shallow suspend mode

Sudeep Holla
2017-02-21T10:42:45Z

Hi Geert,

On 20/02/17 20:33, Geert Uytterhoeven wrote:
> Enable support for "shallow" suspend mode, also known as "Standby" or
> "Power-On Suspend".
>
> As secondary CPU cores are taken offline, "shallow" suspend mode saves
> slightly more power than "s2idle", but less than "deep" suspend mode.
> However, unlike "deep" suspend mode, "shallow" suspend mode can be used
> regardless of the presence of support for PSCI_SYSTEM_SUSPEND, which is
> an optional API in PSCI v1.0.
>
> List the available system suspend modes:
>
> $ cat /sys/power/mem_sleep
> s2idle shallow [deep]
>
> Suspend to "shallow" mode:
>
> $ echo shallow > /sys/power/mem_sleep
> $ echo mem > /sys/power/state
>

I don't have the links to such previous attempts handy, but we have
more elegant alternative options(suspend-to-idle) and any such attempts
to hack around the PSCI will be NACKed.

--
Regards,
Sudeep