X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=arch%2Fx86%2Fkernel%2Fhpet.c;h=59fd3b6b13036e1e279e54d0e1e3d3f5ebb55166;hb=b9b50363e6c60d471fe2e71e48d434aad58b3749;hp=0ea6a19bfdfead682bbee695f165b05e9e4b9070;hpb=5554b35933245e95710d709175e14c02cbc956a4;p=linux-2.6

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 0ea6a19bfd..59fd3b6b13 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -359,6 +359,7 @@ static int hpet_clocksource_register(void)
 int __init hpet_enable(void)
 {
 	unsigned long id;
+	int i;
 
 	if (!is_hpet_capable())
 		return 0;
@@ -369,6 +370,29 @@ int __init hpet_enable(void)
 	 * Read the period and check for a sane value:
 	 */
 	hpet_period = hpet_readl(HPET_PERIOD);
+
+	/*
+	 * AMD SB700 based systems with spread spectrum enabled use a
+	 * SMM based HPET emulation to provide proper frequency
+	 * setting. The SMM code is initialized with the first HPET
+	 * register access and takes some time to complete. During
+	 * this time the config register reads 0xffffffff. We check
+	 * for max. 1000 loops whether the config register reads a non
+	 * 0xffffffff value to make sure that HPET is up and running
+	 * before we go further. A counting loop is safe, as the HPET
+	 * access takes thousands of CPU cycles. On non SB700 based
+	 * machines this check is only done once and has no side
+	 * effects.
+	 */
+	for (i = 0; hpet_readl(HPET_CFG) == 0xFFFFFFFF; i++) {
+		if (i == 1000) {
+			printk(KERN_WARNING
+			       "HPET config register value = 0xFFFFFFFF. "
+			       "Disabling HPET\n");
+			goto out_nohpet;
+		}
+	}
+
 	if (hpet_period < HPET_MIN_PERIOD || hpet_period > HPET_MAX_PERIOD)
 		goto out_nohpet;
 
@@ -468,7 +492,7 @@ void hpet_disable(void)
 #define RTC_NUM_INTS		1
 
 static unsigned long hpet_rtc_flags;
-static unsigned long hpet_prev_update_sec;
+static int hpet_prev_update_sec;
 static struct rtc_time hpet_alarm_time;
 static unsigned long hpet_pie_count;
 static unsigned long hpet_t1_cmp;
@@ -575,6 +599,9 @@ int hpet_set_rtc_irq_bit(unsigned long bit_mask)
 
 	hpet_rtc_flags |= bit_mask;
 
+	if ((bit_mask & RTC_UIE) && !(oldbits & RTC_UIE))
+		hpet_prev_update_sec = -1;
+
 	if (!oldbits)
 		hpet_rtc_timer_init();
 
@@ -652,7 +679,7 @@ static void hpet_rtc_timer_reinit(void)
 		if (hpet_rtc_flags & RTC_PIE)
 			hpet_pie_count += lost_ints;
 		if (printk_ratelimit())
-			printk(KERN_WARNING "rtc: lost %d interrupts\n",
+			printk(KERN_WARNING "hpet1: lost %d rtc interrupts\n",
 				lost_ints);
 	}
 }
@@ -670,7 +697,8 @@ irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
 
 	if (hpet_rtc_flags & RTC_UIE &&
 	    curr_time.tm_sec != hpet_prev_update_sec) {
-		rtc_int_flag = RTC_UF;
+		if (hpet_prev_update_sec >= 0)
+			rtc_int_flag = RTC_UF;
 		hpet_prev_update_sec = curr_time.tm_sec;
 	}