Re: [PATCH] ACPI: implement acpi_os_get_timer() according the spec

From: Rafael J. Wysocki
Date: Mon May 13 2013 - 07:30:22 EST


On Monday, May 13, 2013 01:27:51 PM Mika Westerberg wrote:
> ACPI Timer() opcode should return monotonically increasing clock with 100ns
> granularity. Implement this with the help of ktime_get().
>
> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>

That looks reasobable. Have you tested it?

Rafael


> ---
> drivers/acpi/osl.c | 14 +-------------
> 1 file changed, 1 insertion(+), 13 deletions(-)
>
> diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
> index 586e7e9..2a22170 100644
> --- a/drivers/acpi/osl.c
> +++ b/drivers/acpi/osl.c
> @@ -835,19 +835,7 @@ 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;
> + return ktime_to_ns(ktime_get()) / 100;
> }
>
> acpi_status acpi_os_read_port(acpi_io_address port, u32 * value, u32 width)
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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