@@ -835,19 +835,9 @@ void acpi_os_stall(u32 us)
*/
u64 acpi_os_get_timer(void)
{
- static u64 t;
-
-#ifdef CONFIG_HPET
- /* TBD: use HPET if available */
-#endif
-
-#ifdef CONFIG_X86_PM_TIMER
- /* TBD: default to PM timer if HPET was not available */
-#endif
- if (!t)
- printk(KERN_ERR PREFIX "acpi_os_get_timer() TBD\n");
-
- return ++t;
+ u64 time_ns = ktime_to_ns(ktime_get());
+ do_div(time_ns, 100);
+ return time_ns;
}
acpi_status acpi_os_read_port(acpi_io_address port, u32 * value, u32 width)
ACPI Timer() opcode should return monotonically increasing clock with 100ns granularity according the ACPI 5.0 spec. Testing the current Timer() implementation with following ASL code (and an additional debug print in acpi_os_sleep() to get the sleep times dumped out to dmesg): // Test: 10ms Store(Timer, Local1) Sleep(10) Divide(Subtract(Timer, Local1), 10000,, Local1) Sleep(Local1) // Test: 200ms Store(Timer, Local1) Sleep(200) Divide(Subtract(Timer, Local1), 10000,, Local1) Sleep(Local1) // Test 1300ms Store(Timer, Local1) Sleep(1300) Divide(Subtract(Timer, Local1), 10000,, Local1) Sleep(Local1) The second sleep value is calculated using Timer(). If the implementation is good enough we should be able to get the second value pretty close to the first. However, the current Timer() gives pretty bad sleep times: [ 11.488100] ACPI: acpi_os_get_timer() TBD [ 11.492150] ACPI: Sleep(10) [ 11.502993] ACPI: Sleep(0) [ 11.506315] ACPI: Sleep(200) [ 11.706237] ACPI: Sleep(0) [ 11.709550] ACPI: Sleep(1300) [ 13.008929] ACPI: Sleep(0) Fix this with the help of ktime_get(). Once the fix is applied and run against the same ASL code we get: [ 11.486786] ACPI: Sleep(10) [ 11.499029] ACPI: Sleep(12) [ 11.512350] ACPI: Sleep(200) [ 11.712282] ACPI: Sleep(200) [ 11.912170] ACPI: Sleep(1300) [ 13.211577] ACPI: Sleep(1300) That is much more closer to the values we expected. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> --- Difference to the previous version is that now we use do_div() instead so that i386 build won't break. This was found by kbuild test robot. In addition I tested this on both i386 and x86_64. drivers/acpi/osl.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-)