Power management in 2.6 and ACPI - are the pm_registered functions used?

Here is the problem: When using ACPI - if I go to S1/S3 on an inspiron
8200, on power restore, the vga console is garbage - unless X is
running and a console switch usually solves the problem. This is suboptimal. 


I have ascertained that upon restoration of power, the console backlight is
disabled - which is one of the problems - but I suspect that the vga console
can get into a weird state in low power mode which needs to be restored.

The more underlying problem stems from how power management is handled:
Under apm the pm_send_all is invoked to notify devices and then the device
power handling is invoked, with ACPI, the pm_regsitered interface is ignored.

Would it make sense for drivers/video/console/vgacon.c to register
itself as a device? Then it could handle power requests directly and
the pm_send_all could be ignored. Or is the first solution for
pm_send_all be added to kernel/power/main.c.

It is entertaining in that the vga console is sort of on a bus - the
pci bus on one machine - but may be on a baseboad... Does one try to
pci_register_driver? Does one create a system class? Interesting dilemma.

Any thoughts?

Ezra

-----------------------------------------------------------------------

The following described the code paths involved:

With apm - on a 386, arch/i386/kernel/apm.c: in suspend(), the
following logic exists:


	if (pm_send_all(PM_SUSPEND, (void *)3)) {
		/* Vetoed */
....

	device_suspend(3);

--------------------------------------------------
In ACPI:  drivers/acpi/sleep/main.c: acpi_suspend() 

     This invokes pm_suspend

  ... In kernel/power/main.c: pm_suspend invokes enter_state(), suspend_prepare(), which then invokes device_suspend().
--------------------------------------------------------

In the sysfs interface: enter_state is used...

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