[066/165] x86: Do not try to disable hpet if it hasnt been initialized before

From: Greg KH
Date: Fri Jul 30 2010 - 15:05:41 EST

2.6.32-stable review patch. If anyone has any objections, please let us know.


From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>

commit ff4878089e1eaeac79d57878ad4ea32910fb4037 upstream.

hpet_disable is called unconditionally on machine reboot if hpet support
is compiled in the kernel.
hpet_disable only checks if the machine is hpet capable but doesn't make
sure that hpet has been initialized.

[ tglx: Made it a one liner and removed the redundant hpet_address check ]

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Acked-by: Venkatesh Pallipadi <venki@xxxxxxxxxx>
LKML-Reference: <alpine.DEB.2.00.1007211726240.22235@kaball-desktop>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

arch/x86/kernel/hpet.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -949,7 +949,7 @@ fs_initcall(hpet_late_init);

void hpet_disable(void)
- if (is_hpet_capable()) {
+ if (is_hpet_capable() && hpet_virt_address) {
unsigned long cfg = hpet_readl(HPET_CFG);

if (hpet_legacy_int_enabled) {

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