This patch adds quirks to force enable HPET on Via VT8235 and
VT8237 chipsets. The datasheet for 8237 documents HPET
functionality (although wrongly) whereas HPET is undocumented
for 8235.
Tested on A7V880 (8237) and K7VT4A+ (8235) boards.
tglx: depends on the force_hept commandline option
Signed-off-by: Udo A. Steinberg <us15@os.inf.tu-dresden.de>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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 <venkatesh.pallipadi@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>