Subject: [RFC][PATCH] x86_64:  Fix collision between pmtimer and pit/hpet
	timekeeping
From: john stultz <johnstul@us.ibm.com>
To: lkml <linux-kernel@vger.kernel.org>
Cc: Chris McDermott <lcm@us.ibm.com>, Andi Kleen <ak@suse.de>
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Date: Tue, 06 Dec 2005 21:00:39 -0800
Message-Id: <1133931639.10613.39.camel@cog.beaverton.ibm.com>
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Hello,
	I thought I had caught all the problems when the no-legacy HPET support
landed close to the time that the ACPI PM timer support landed, but
apparently not. :(

On systems that do not support the HPET legacy functions (basically the
IBM x460, but there could be others), in time_init() we accidentally
fall into a PM timer conditional and set the vxtime_hz value to the PM
timer's frequency. We then use this value with the HPET for timekeeping.

This patch (which mimics the behavior in time_init_gtod) corrects the
collision.

Andi, any objections or suggestions for a better way?

thanks
-john

diff --git a/arch/x86_64/kernel/time.c b/arch/x86_64/kernel/time.c
index fdaddc4..fb389d2 100644
--- a/arch/x86_64/kernel/time.c
+++ b/arch/x86_64/kernel/time.c
@@ -913,7 +913,7 @@ void __init time_init(void)
 		cpu_khz = hpet_calibrate_tsc();
 		timename = "HPET";
 #ifdef CONFIG_X86_PM_TIMER
-	} else if (pmtmr_ioport) {
+	} else if (pmtmr_ioport && !vxtime.hpet_address) {
 		vxtime_hz = PM_TIMER_FREQUENCY;
 		timename = "PM";
 		pit_init();


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