[U-Boot] [RFC][Timer API] Revised Specification - Implementation details

Graeme Russ
2011-05-27T07:57:40Z

Hi Wolfgang

On Friday, May 27, 2011, Wolfgang Denk <wd@denx.de> wrote:
> Dear Graeme Russ,
>
> In message <4DDF543D.6020506@gmail.com> you wrote:
>>
>> >> I think we will need to define get_timer() weak - Nios will have to
>> >> override the default implementation to cater for it's (Nios') limitations
>> >
>> > Please don't ?- isn't the purpose of this whole discussion to use
>> > common code for this ?
>> >
>>
>> Yes, but Nios is particularly bad - It has a 10ms tick counter :(
>>
>> I don't see reason for hamstring other platforms when a simply weak
>> function can get around it
>
> Why does NIOS require a different get_timer() implementation?
>
> Nobody claims that get_timer() has any specific resolution. It is
> perfectly legal that a loop like
>
> ? ? ? ?for (;;) {
> ? ? ? ? ? ? ? ?u32 t = get_time();
>
> ? ? ? ? ? ? ? ?printf("t=%ul\n", t);
> ? ? ? ?}
>
> returns 100 millisecond increments.

Except everyone expects it to tick at something vaguely close to 1ms.
When you comment about accuracy, I didn't expect 1000% error was
acceptable...

Regards,

Graeme