[CPUFREQ] Longhaul: Magic timer frobbing.

As mandated by the spec, disable timer around transitions.

From code by : Ken Staton <ken_staton@agilent.com
Signed-off-by: Dave Jones <davej@redhat.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/arch/i386/kernel/cpu/cpufreq/longhaul.c b/arch/i386/kernel/cpu/cpufreq/longhaul.c
index 8ea545e35b3a..48899f0956f7 100644
--- a/arch/i386/kernel/cpu/cpufreq/longhaul.c
+++ b/arch/i386/kernel/cpu/cpufreq/longhaul.c
@@ -120,9 +120,10 @@ static int longhaul_get_cpu_mult(void)
 static void do_powersaver(union msr_longhaul *longhaul,
                         unsigned int clock_ratio_index)
 {
-        int version;
-        unsigned long flags;
         struct pci_dev *dev;
+        unsigned long flags;
+        unsigned int tmp_mask;
+        int version;
         int i;
         u16 pci_cmd;
         u16 cmd_state[64];
@@ -163,6 +164,10 @@ static void do_powersaver(union msr_longhaul *longhaul,
                 }
         } while (dev != NULL);
 
+        tmp_mask=inb(0x21);     /* works on C3. save mask. */
+        outb(0xFE,0x21);        /* TMR0 only */
+        outb(0xFF,0x80);        /* delay */
+
         local_irq_enable();
 
         __hlt();
@@ -171,6 +176,8 @@ static void do_powersaver(union msr_longhaul *longhaul,
 
         local_irq_disable();
 
+        outb(tmp_mask,0x21);    /* restore mask */
+
         /* restore pci bus master state for all devices */
         dev = NULL;
         i = 0;