RE: [Xen-devel] [PATCH1/6] cpuidle: fix wrapped ticks calculation for pm timer

["Wei, Gang" <gang.wei@xxxxxxxxx>]

On Thursday, 2010-6-17 4:19 PM, Jan Beulich wrote:
>>>> On 17.06.10 at 09:37, "Wei, Gang" <gang.wei@xxxxxxxxx> wrote:
>> cpuidle: fix wrapped ticks calculation for pm timer.
>> 
>> Signed-off-by: Wei Gang <gang.wei@xxxxxxxxx>
>> 
>> diff -r 26c2922da53c xen/arch/x86/acpi/cpu_idle.c
>> --- a/xen/arch/x86/acpi/cpu_idle.c   Thu May 27 09:39:47 2010 +0100
>> +++ b/xen/arch/x86/acpi/cpu_idle.c   Sun Jun 13 06:44:32 2010 +0800
>> @@ -137,9 +137,9 @@ static inline u32 ticks_elapsed(u32 t1,      if
>>          ( t2 >= t1 ) return (t2 - t1);
>>      else if ( !(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER) )
>> -        return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
>> +        return (((0x00FFFFFF - t1) + t2 + 1) & 0x00FFFFFF);     
>> else -        return ((0xFFFFFFFF - t1) + t2);
>> +        return ((0xFFFFFFFF - t1) + t2 +1);
> 
> Why can't this then also just be (t2 - t1)?

Yes, you are right. We could simply just let it be (t2 - t1) here. But it would 
depend on the t1/t2 type. Current version didn't depend on the input types 
which will be changed by later patch.

Jimmy 
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel