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From: Tom <Tom.Rix@windriver.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 2/2] ep93xx: Refactoring of timer code
Date: Tue, 23 Feb 2010 20:04:44 -0600	[thread overview]
Message-ID: <4B84893C.8000600@windriver.com> (raw)
In-Reply-To: <20100223224402.GO20201@darwin>

Matthias Kaehlcke wrote:
> Hi Wolfgang,
> 
> El Tue, Feb 23, 2010 at 11:23:42PM +0100 Wolfgang Denk ha dit:
> 
>> In message <20100223220421.GK20201@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!
> 

      reply	other threads:[~2010-02-24  2:04 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <7ee75976e78e2f82b4163fe1ff4233a850d4393c.1266962256.git.matthias@kaehlcke.net>
2010-02-23 22:04 ` [U-Boot] [PATCH 2/2] ep93xx: Refactoring of timer code Matthias Kaehlcke
2010-02-23 22:23   ` Wolfgang Denk
2010-02-23 22:44     ` Matthias Kaehlcke
2010-02-24  2:04       ` Tom [this message]

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