[U-Boot] [PATCH 2/2] ep93xx: Refactoring of timer code

Tom Tom.Rix at windriver.com
Wed Feb 24 03:04:44 CET 2010


Matthias Kaehlcke wrote:
> Hi Wolfgang,
> 
> El Tue, Feb 23, 2010 at 11:23:42PM +0100 Wolfgang Denk ha dit:
> 
>> In message <20100223220421.GK20201 at darwin> you wrote:
>>> ep93xx: Refactoring of the timer code, including the following changes
>> ...
>>> +#define TIMER_FREQ			508469
>>> +#define CLK_TICKS_PER_SYS_TICK		(TIMER_FREQ / CONFIG_SYS_HZ)
>> ...
>>> +		ticks *= (CLK_TICKS_PER_SYS_TICK * CONFIG_SYS_HZ);
>> ...
>>> +		ticks = usecs * CLK_TICKS_PER_SYS_TICK * CONFIG_SYS_HZ;
>> Why don't you use
>>
>> 	ticks *= TIMER_FREQ;
>> resp.
>> 	ticks = usecs * TIMER_FREQ;
>>
>> The combination of " / CONFIG_SYS_HZ * CONFIG_SYS_HZ" is just a bad
>> NO-OP (with rounding errors).
> 
> you certainly have a point, i'm going to change this as you proposed
> 
>> Hm... re-reading the optimized code makes me wonder if the variable
>> really should be called "ticks" - looks more as a frequency to me?
> 
> here i disagree, the function returns the number of ticks that pass in
> a certain number of microseconds, so i think 'ticks' is an appropiate
> name
> 
Perhaps a comment on the units of TIMER_FREQ ?
This is minor point.
Otherwise looks fine.
Tom


> thanks for your review!
> 



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