On Wed, 06 Jun 2007 11:37:53 +0200 Thomas Gleixner <[EMAIL PROTECTED]> wrote:

> From: Udo A. Steinberg <[EMAIL PROTECTED]>
> 
> The chip set doc for IHC4 says:
> 
> 1.In general, software should not attempt any non-posted accesses during
> arbiter disable except to the ICH4's power management registers. This
> implies that interrupt handlers for any unmasked hardware interrupts and
> SMI/NMI should check ARB_DIS status before reading from ICH devices.
> 
> So it's not a good idea to access ICH devices after arbiter shut down. 
> 
> Signed-off-by: Udo A. Steinberg <[EMAIL PROTECTED]>
> Signed-off-by: Thomas Gleixner <[EMAIL PROTECTED]>
> 
> ---
>  drivers/acpi/processor_idle.c |    9 +++++----
>  1 file changed, 5 insertions(+), 4 deletions(-)
> 
> Index: linux-2.6.22-rc4/drivers/acpi/processor_idle.c
> ===================================================================
> --- linux-2.6.22-rc4.orig/drivers/acpi/processor_idle.c       2007-06-06 
> 11:47:21.000000000 +0200
> +++ linux-2.6.22-rc4/drivers/acpi/processor_idle.c    2007-06-06 
> 11:48:21.000000000 +0200
> @@ -488,6 +488,11 @@ static void acpi_processor_idle(void)
>  
>       case ACPI_STATE_C3:
>  
> +             /* Get start time (ticks) */
> +             t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
> +             /* Handle timer broadcast before bus arbiter shutdown ! */
> +             acpi_state_timer_broadcast(pr, cx, 1);
> +
>               if (pr->flags.bm_check) {
>                       if (atomic_inc_return(&c3_cpu_count) ==
>                           num_online_cpus()) {
> @@ -502,10 +507,7 @@ static void acpi_processor_idle(void)
>                       ACPI_FLUSH_CPU_CACHE();
>               }
>  
> -             /* Get start time (ticks) */
> -             t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
>               /* Invoke C3 */
> -             acpi_state_timer_broadcast(pr, cx, 1);
>               acpi_cstate_enter(cx);
>               /* Get end time (ticks) */
>               t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);

hm, this needs a bit of help to get it to work against Len's current tree.

However, if by "non-posted accesses" you're referring to that inl(), how
come the second one which was left in place isn't also a problem?

-
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