From: john stultz <johnstul@us.ibm.com>
Date: Fri, 1 Sep 2006 04:27:37 +0000 (-0700)
Subject: [PATCH] Fix faulty HPET clocksource usage (fix for bug #7062)
X-Git-Tag: v3.12-rc1~34152
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=30f3174d1c506db2c6d2c1dddc9c064e741d6b76;p=kernel%2Fkernel-generic.git

[PATCH] Fix faulty HPET clocksource usage (fix for bug #7062)

Apparently some systems export valid HPET addresses, but hpet_enable()
fails.  Then when the HPET clocksource starts up, it only checks for a
valid HPET address, and the result is a system where time does not advance.

See http://bugme.osdl.org/show_bug.cgi?id=7062 for details.

This patch just makes sure we better check that the HPET is functional
before registering the HPET clocksource.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/arch/i386/kernel/hpet.c b/arch/i386/kernel/hpet.c
index c6737c3..17647a5 100644
--- a/arch/i386/kernel/hpet.c
+++ b/arch/i386/kernel/hpet.c
@@ -35,7 +35,7 @@ static int __init init_hpet_clocksource(void)
 	void __iomem* hpet_base;
 	u64 tmp;
 
-	if (!hpet_address)
+	if (!is_hpet_enabled())
 		return -ENODEV;
 
 	/* calculate the hpet address: */