From 7cfb0435330364f90f274a26ecdc5f47f738498c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 3 Sep 2008 21:37:24 +0000 Subject: [PATCH] HPET: make minimum reprogramming delta useful The minimum reprogramming delta was hardcoded in HPET ticks, which is stupid as it does not work with faster running HPETs. The C1E idle patches made this prominent on AMD/RS690 chipsets, where the HPET runs with 25MHz. Set it to 5us which seems to be a reasonable value and fixes the problems on the bug reporters machines. We have a further sanity check now in the clock events, which increases the delta when it is not sufficient. Signed-off-by: Thomas Gleixner Tested-by: Luiz Fernando N. Capitulino Tested-by: Dmitry Nezhevenko Signed-off-by: Ingo Molnar --- arch/x86/kernel/hpet.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index 59fd3b6b1303..2256315416d8 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -210,8 +210,8 @@ static void hpet_legacy_clockevent_register(void) /* Calculate the min / max delta */ hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF, &hpet_clockevent); - hpet_clockevent.min_delta_ns = clockevent_delta2ns(0x30, - &hpet_clockevent); + /* 5 usec minimum reprogramming delta. */ + hpet_clockevent.min_delta_ns = 5000; /* * Start hpet with the boot cpu mask and make it -- 2.30.2