Re: [PATCH 4/7] PM / Domains: Rework system suspend callback routines

Pavel Machek
2012-02-17T19:29:37Z

On Mon 2011-11-07 01:08:11, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@sisk.pl>
>
> The current generic PM domains code attempts to use the generic
> system suspend operations along with the domains' device stop/start
> routines, which requires device drivers to assume that their
> system suspend/resume (and hibernation/restore) callbacks will always
> be used with generic PM domains. However, in theory, the same
> hardware may be used in devices that don't belong to any PM domain,
> in which case it would be necessary to add "fake" PM domains to
> satisfy the above assumption. Also, the domain the hardware belongs
> to may not be handled with the help of the generic code.
>
> To allow device drivers that may be used along with the generic PM
> domains code of more flexibility, add new device callbacks, .freeze(),
> .freeze_late(), .thaw_early() and .thaw(), that can be supplied by
> the drivers in addition to their "standard" system suspend and
> hibernation callbacks. These new callbacks, if defined, will be used
> by the generic PM domains code for the handling of system suspend and
> hibernation instead of the "standard" ones. This will allow drivers
> to be designed to work with generic PM domains as well as without
> them.

Should this go to Documentation/ somewhere? May concern is that we
have way too many callbacks these days. Why is fake PM domain such a
bad thing?
Pavel
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