diff options
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/acpi_pm.c | 53 |
1 files changed, 32 insertions, 21 deletions
diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c index 5ca1d80de18..71d2ac4e3f4 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 +176,15 @@ 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 +/* Number of reads we try to get two different values */ +#define ACPI_PM_READ_CHECKS 10000 + static int __init init_acpi_pm_clocksource(void) { - u32 value1, value2; - unsigned int i; + cycle_t value1, value2; + unsigned int i, j = 0; if (!pmtmr_ioport) return -ENODEV; @@ -187,24 +193,29 @@ 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++) { + udelay(100 * j); + value1 = clocksource_acpi_pm.read(); + for (i = 0; i < ACPI_PM_READ_CHECKS; i++) { + value2 = clocksource_acpi_pm.read(); + if (value2 == value1) + continue; + if (value2 > value1) + break; + if ((value2 < value1) && ((value2) < 0xFFF)) + break; + printk(KERN_INFO "PM-Timer had inconsistent results:" + " 0x%#llx, 0x%#llx - aborting.\n", + value1, value2); + return -EINVAL; + } + if (i == ACPI_PM_READ_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; |