[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>
diff --git a/arch/i386/kernel/cpu/cpufreq/longhaul.c b/arch/i386/kernel/cpu/cpufreq/longhaul.c
index 8ea545e..48899f0 100644
--- a/arch/i386/kernel/cpu/cpufreq/longhaul.c
+++ b/arch/i386/kernel/cpu/cpufreq/longhaul.c
@@ -120,9 +120,10 @@
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 @@
}
} 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 @@
local_irq_disable();
+ outb(tmp_mask,0x21); /* restore mask */
+
/* restore pci bus master state for all devices */
dev = NULL;
i = 0;