From d54bd57d6580250e6551261f3b15c45a9d90c77b Mon Sep 17 00:00:00 2001 From: Venki Pallipadi Date: Fri, 12 Oct 2007 23:04:23 +0200 Subject: x86: HPET force enable o ICH7 and later Force detect and/or enable HPET on ICH chipsets. This patch just handles the detection part and following patches use this information. Adds a function to repeat the force enabling during resume time. Using HPET this way, instead of PIT increases the time CPUs can reside in C-state when system is totally idle. On my test system with Core 2 Duo, average C-state residency goes up from ~20mS to ~80mS. [ Build fixed from Andrew Morton ] Signed-off-by: Venkatesh Pallipadi Cc: Andi Kleen Cc: john stultz Cc: Greg KH Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Thomas Gleixner --- include/asm-x86/hpet.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/asm-x86/hpet.h') diff --git a/include/asm-x86/hpet.h b/include/asm-x86/hpet.h index 64446a9577dc..7c933242365f 100644 --- a/include/asm-x86/hpet.h +++ b/include/asm-x86/hpet.h @@ -66,6 +66,7 @@ extern unsigned long hpet_address; extern int is_hpet_enabled(void); extern int hpet_enable(void); extern unsigned long hpet_readl(unsigned long a); +extern void ich_force_hpet_resume(void); #ifdef CONFIG_HPET_EMULATE_RTC -- cgit v1.2.3