[patch] swsusp2 should execute _WAK on resume

[Lorenzo Colitti <lorenzo-Z4WAQ3j+MphBDgjK7y7TUQ@public.gmane.org>]

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Hi,

[CCing ACPI-devel in case someone wants to comment]

Using swsusp2 2.1.8 on a vanilla 2.6.11 kernel (but I have been seeing 
this since v2.1 on 2.6.9), my laptop (HP nc6000) doesn't generate any 
ACPI thermal events after resume. This means the fans only come on 
(screaming) if the CPU reaches 85 °C or so, which is not very healthy.

This is due to the fact that unlike swsusp and S3, swsusp2 does not call 
the ACPI _WAK method, which the ACPI spec says should be called when the 
machine comes out of a sleep state. If I hack swsusp2 so that it calls 
the _WAK method on resume, the fans work correctly after resume.

I do this via the attached hack, but I don't know much about the 
workings of swsusp2, so I don't know if it's the right approach. It does 
work for me though, and even if the details of the patch aren't right, 
based on my reading of the ACPI spec I think this should be done.

Comments? Is it fit to apply to the swsusp2 tree?


Cheers,
Lorenzo

P.S. I have been using swsusp2 since v2.1 for 2.6.9, and it works like a 
charm. A big thank you to the people that made it possible. :)

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diff -u linux-2.6.11/kernel/power/suspend2_core/suspend.c linux-2.6.11-patched/kernel/power/suspend2_core/suspend.c
--- linux-2.6.11/kernel/power/suspend2_core/suspend.c	2005-03-07 15:17:31.000000000 +0100
+++ linux-2.6.11-patched/kernel/power/suspend2_core/suspend.c	2005-03-07 15:18:47.000000000 +0100
@@ -404,6 +404,10 @@
  * Called From     : do_suspend2_lowlevel
  */
 
+#ifdef CONFIG_ACPI
+extern u32 acpi_leave_sleep_state (u8 sleep_state);
+#endif
+
 static void do_suspend2_resume_2(void)
 {
 	set_suspend_state(SUSPEND_NOW_RESUMING);
@@ -433,6 +437,11 @@
 	suspend_checksum_print_differences();
 
 	prepare_status(0, 0, "Cleaning up...");
+
+#ifdef CONFIG_ACPI
+	if (suspend_powerdown_method)
+		acpi_leave_sleep_state(suspend_powerdown_method);
+#endif
 }
 
 /*