diff options
| -rw-r--r-- | drivers/acpi/osl.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 8df9abfa947b..ed73f6fb0779 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -617,15 +617,18 @@ void acpi_os_stall(u32 us) } /* - * Support ACPI 3.0 AML Timer operand - * Returns 64-bit free-running, monotonically increasing timer - * with 100ns granularity + * Support ACPI 3.0 AML Timer operand. Returns a 64-bit free-running, + * monotonically increasing timer with 100ns granularity. Do not use + * ktime_get() to implement this function because this function may get + * called after timekeeping has been suspended. Note: calling this function + * after timekeeping has been suspended may lead to unexpected results + * because when timekeeping is suspended the jiffies counter is not + * incremented. See also timekeeping_suspend(). */ u64 acpi_os_get_timer(void) { - u64 time_ns = ktime_to_ns(ktime_get()); - do_div(time_ns, 100); - return time_ns; + return (get_jiffies_64() - INITIAL_JIFFIES) * + (ACPI_100NSEC_PER_SEC / HZ); } acpi_status acpi_os_read_port(acpi_io_address port, u32 * value, u32 width) |