releases/2.6.32.17/x86-do-not-try-to-disable-hpet-if-it-hasn-t-been-initialized-before.patch

   1 From ff4878089e1eaeac79d57878ad4ea32910fb4037 Mon Sep 17 00:00:00 2001
   2 From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
   3 Date: Wed, 21 Jul 2010 18:32:37 +0100
   4 Subject: x86: Do not try to disable hpet if it hasn't been initialized before
   5
   6 From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
   7
   8 commit ff4878089e1eaeac79d57878ad4ea32910fb4037 upstream.
   9
  10 hpet_disable is called unconditionally on machine reboot if hpet support
  11 is compiled in the kernel.
  12 hpet_disable only checks if the machine is hpet capable but doesn't make
  13 sure that hpet has been initialized.
  14
  15 [ tglx: Made it a one liner and removed the redundant hpet_address check ]
  16
  17 Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
  18 Acked-by: Venkatesh Pallipadi <venki@google.com>
  19 LKML-Reference: <alpine.DEB.2.00.1007211726240.22235@kaball-desktop>
  20 Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  21 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  22
  23 ---
  24  arch/x86/kernel/hpet.c |    2 +-
  25  1 file changed, 1 insertion(+), 1 deletion(-)
  26
  27 --- a/arch/x86/kernel/hpet.c
  28 +++ b/arch/x86/kernel/hpet.c
  29 @@ -949,7 +949,7 @@ fs_initcall(hpet_late_init);
  30
  31  void hpet_disable(void)
  32  {
  33 -       if (is_hpet_capable()) {
  34 +       if (is_hpet_capable() && hpet_virt_address) {
  35                 unsigned long cfg = hpet_readl(HPET_CFG);
  36
  37                 if (hpet_legacy_int_enabled) {