[U-Boot] [RFC] ARM timing code refactoring

[Wolfgang Denk <wd@denx.de>]

Dear Reinhard Meyer,

In message <4D3D2F34.6020903@emk-elektronik.de> you wrote:
> Dear all,
> 
> its quite funny to see how we go around in circles here, this proposal of Albert
> now is quite close to my original proposal. Only that I factored the ms_to_ticks
> AND the comparison into the timer calls:
> 
> u64 timer_setup(u32 timeout_in_ms)
> {
> 	return get_ticks() + ms_to_ticks(timeout_in_ms);
> }

No.  I said this severaltimes before, and I repeat it here one other
time:  I do not want to see such a function.  There nothing to be done
to "set up a timer".


> 	/*
> 	 * convert the unsigned difference to signed, to easyly
> 	 * check for "carry". In assembly we could just do a BCC
> 	 * after the subtraction to see whether get_ticks()
> 	 * has passed ahead of endtime.
> 	 */
> 	return (signed)(endtime - get_ticks()) < 0;

Are you sure this is really working? Why do you insist on this
approach instead of using the proven to be correct way to write this?

> > 	u32 start = get_timer(); /* start time, in ticks */

No. I do not see any reason to change existing interfaces.

If ticks are wanted, then use get_ticks().  And deal with the overhead
or 64 bit arithmetics.

But in general code I prefer get_timer() - milliseconds, u32.

Best regards,

Wolfgang Denk

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