x86: Do not try to disable hpet if it hasn't been initialized before

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@eu.citrix.com>
Acked-by: Venkatesh Pallipadi <venki@google.com>
LKML-Reference: <alpine.DEB.2.00.1007211726240.22235@kaball-desktop>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 773afc9274a14c6984e1d3ddfc1f2c4119ed500f..241c5b24b349220374d2ecd7ebd6ff5d4a985b43 100644 (file)
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -958,7 +958,7 @@ fs_initcall(hpet_late_init);
 
 void hpet_disable(void)
 {
-       if (is_hpet_capable()) {
+       if (is_hpet_capable() && hpet_virt_address) {
                unsigned int cfg = hpet_readl(HPET_CFG);
 
                if (hpet_legacy_int_enabled) {