x86: fix cpu MHz reporting for AMD family 0x11

[linux-2.6-omap-h63xx.git] / arch / x86 / kernel / mfgpt_32.c

diff --git a/arch/x86/kernel/mfgpt_32.c b/arch/x86/kernel/mfgpt_32.c
index 0ab680f2d9db9af7885e9d5eedc9c02b79cd72d2..219f86eb612301766771651eb56cb1e8f98189ac 100644 (file)
--- a/arch/x86/kernel/mfgpt_32.c
+++ b/arch/x86/kernel/mfgpt_32.c
@@ -63,6 +63,21 @@ static int __init mfgpt_disable(char *s)
 }
 __setup("nomfgpt", mfgpt_disable);
 
+/* Reset the MFGPT timers. This is required by some broken BIOSes which already
+ * do the same and leave the system in an unstable state. TinyBIOS 0.98 is
+ * affected at least (0.99 is OK with MFGPT workaround left to off).
+ */
+static int __init mfgpt_fix(char *s)
+{
+       u32 val, dummy;
+
+       /* The following udocumented bit resets the MFGPT timers */
+       val = 0xFF; dummy = 0;
+       wrmsr(0x5140002B, val, dummy);
+       return 1;
+}
+__setup("mfgptfix", mfgpt_fix);
+
 /*
  * Check whether any MFGPTs are available for the kernel to use.  In most
  * cases, firmware that uses AMD's VSA code will claim all timers during
@@ -278,12 +293,12 @@ static int mfgpt_next_event(unsigned long delta, struct clock_event_device *evt)
 
 static irqreturn_t mfgpt_tick(int irq, void *dev_id)
 {
+       /* Turn off the clock (and clear the event) */
+       mfgpt_disable_timer(mfgpt_event_clock);
+
        if (mfgpt_tick_mode == CLOCK_EVT_MODE_SHUTDOWN)
                return IRQ_HANDLED;
 
-       /* Turn off the clock */
-       mfgpt_disable_timer(mfgpt_event_clock);
-
        /* Clear the counter */
        geode_mfgpt_write(mfgpt_event_clock, MFGPT_REG_COUNTER, 0);
 
@@ -319,10 +334,6 @@ static int __init mfgpt_timer_setup(void)
        }
 
        mfgpt_event_clock = timer;
-       /* Set the clock scale and enable the event mode for CMP2 */
-       val = MFGPT_SCALE | (3 << 8);
-
-       geode_mfgpt_write(mfgpt_event_clock, MFGPT_REG_SETUP, val);
 
        /* Set up the IRQ on the MFGPT side */
        if (geode_mfgpt_setup_irq(mfgpt_event_clock, MFGPT_CMP2, irq)) {
@@ -339,6 +350,11 @@ static int __init mfgpt_timer_setup(void)
                goto err;
        }
 
+       /* Set the clock scale and enable the event mode for CMP2 */
+       val = MFGPT_SCALE | (3 << 8);
+
+       geode_mfgpt_write(mfgpt_event_clock, MFGPT_REG_SETUP, val);
+
        /* Set up the clock event */
        mfgpt_clockevent.mult = div_sc(MFGPT_HZ, NSEC_PER_SEC, 32);
        mfgpt_clockevent.min_delta_ns = clockevent_delta2ns(0xF,