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path: root/drivers/clocksource/acpi_pm.c
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Diffstat (limited to 'drivers/clocksource/acpi_pm.c')
-rw-r--r--drivers/clocksource/acpi_pm.c54
1 files changed, 33 insertions, 21 deletions
diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
index 5ca1d80de182..4eee533f3f4a 100644
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -21,6 +21,7 @@
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/pci.h>
+#include <linux/delay.h>
#include <asm/io.h>
/*
@@ -151,13 +152,13 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_LE,
*/
static int verify_pmtmr_rate(void)
{
- u32 value1, value2;
+ cycle_t value1, value2;
unsigned long count, delta;
mach_prepare_counter();
- value1 = read_pmtmr();
+ value1 = clocksource_acpi_pm.read();
mach_countup(&count);
- value2 = read_pmtmr();
+ value2 = clocksource_acpi_pm.read();
delta = (value2 - value1) & ACPI_PM_MASK;
/* Check that the PMTMR delta is within 5% of what we expect */
@@ -175,10 +176,13 @@ static int verify_pmtmr_rate(void)
#define verify_pmtmr_rate() (0)
#endif
+/* Number of monotonicity checks to perform during initialization */
+#define ACPI_PM_MONOTONICITY_CHECKS 10
+
static int __init init_acpi_pm_clocksource(void)
{
- u32 value1, value2;
- unsigned int i;
+ cycle_t value1, value2;
+ unsigned int i, j, good = 0;
if (!pmtmr_ioport)
return -ENODEV;
@@ -187,24 +191,32 @@ static int __init init_acpi_pm_clocksource(void)
clocksource_acpi_pm.shift);
/* "verify" this timing source: */
- value1 = read_pmtmr();
- for (i = 0; i < 10000; i++) {
- value2 = read_pmtmr();
- if (value2 == value1)
- continue;
- if (value2 > value1)
- goto pm_good;
- if ((value2 < value1) && ((value2) < 0xFFF))
- goto pm_good;
- printk(KERN_INFO "PM-Timer had inconsistent results:"
- " 0x%#x, 0x%#x - aborting.\n", value1, value2);
- return -EINVAL;
+ for (j = 0; j < ACPI_PM_MONOTONICITY_CHECKS; j++) {
+ value1 = clocksource_acpi_pm.read();
+ for (i = 0; i < 10000; i++) {
+ value2 = clocksource_acpi_pm.read();
+ if (value2 == value1)
+ continue;
+ if (value2 > value1)
+ good++;
+ break;
+ if ((value2 < value1) && ((value2) < 0xFFF))
+ good++;
+ break;
+ printk(KERN_INFO "PM-Timer had inconsistent results:"
+ " 0x%#llx, 0x%#llx - aborting.\n",
+ value1, value2);
+ return -EINVAL;
+ }
+ udelay(300 * i);
+ }
+
+ if (good != ACPI_PM_MONOTONICITY_CHECKS) {
+ printk(KERN_INFO "PM-Timer failed consistency check "
+ " (0x%#llx) - aborting.\n", value1);
+ return -ENODEV;
}
- printk(KERN_INFO "PM-Timer had no reasonable result:"
- " 0x%#x - aborting.\n", value1);
- return -ENODEV;
-pm_good:
if (verify_pmtmr_rate() != 0)
return -ENODEV;