Re: [PATCH 02/13] PM: Add early suspend api.

[Pavel Machek <pavel@ucw.cz>]

> +Early-suspend
> +=============
> +
> +The early-suspend api allows drivers to get notified when user-space writes to 
> +/sys/power/request_state to indicate that the user visible sleep state should 
> +change. 

"User visible sleep state"... hmm, PC developers are not going to
understand this.

> A level controls what order the handlers are called in. Suspend 
> +handlers are called in low to high level order, resume handlers are called in 
> +the opposite order. 
> +
> +Four levels are defined:
> +EARLY_SUSPEND_LEVEL_BLANK_SCREEN:
> +  On suspend the screen should be turned off but the framebuffer must still be
> +  accessible. On resume the screen can be turned back on.
> +

Blanking screen is traditionally done at user level? Why does this
need to be in kernel?

> +EARLY_SUSPEND_LEVEL_STOP_DRAWING:
> +  On suspend this level notifies user-space that it should stop accessing the 
> +  framebuffer and it waits for it to complete. On resume it notifies user-space 
> +  that it should resume screen access.


> +  Two methods are provided, console switch or a sysfs interface.

Yeah. Pick one.

> +EARLY_SUSPEND_LEVEL_DISABLE_FB:
> +  Turn off the framebuffer on suspend and back on on resume.
> +
> +EARLY_SUSPEND_LEVEL_STOP_INPUT:
> +  On suspend turn off input devices that are not capable of wakeup or where
> +  wakeup is disabled. On resume turn the same devices back on.

At this point I don't see why early suspend should be done in
kernel. Framebuffer control is better left to userspace... and turning
off input devices should not require this kind of API.
								Pavel
-- 
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