From mboxrd@z Thu Jan  1 00:00:00 1970
From: Matthias Kaehlcke <matthias@kaehlcke.net>
Date: Thu, 25 Feb 2010 20:47:46 +0100
Subject: [U-Boot] [PATCH 2/2 rev2] ep93xx: Refactoring of timer code
In-Reply-To: <20100225192259.GA31347@morgana.gnudd.com>
References: <20100225181528.GA3628@darwin>
	<7ee75976e78e2f82b4163fe1ff4233a850d4393c.1266966938.git.matthias@kaehlcke.net>
	<20100223232209.GR20201@darwin> <4B869D53.1040207@windriver.com>
	<20100225192259.GA31347@morgana.gnudd.com>
Message-ID: <20100225194746.GC3628@darwin>
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To: u-boot@lists.denx.de

Hi,

El Thu, Feb 25, 2010 at 08:22:59PM +0100 Alessandro Rubini ha dit:

> > i was/am working on a new version of the patch, taking into account
> > your remarks about the unit of TIMER_FREQ and fixing some issues
> > discussed with Alessandro Rubini off-list, who worked on a similar
> > patch.
> 
> Actually, I checked the point we disagreed about, which is the unit of
> get_ticks() and get_tbclk().  You currently return hw-ticks in
> get_ticks, and CONFIG_SYS_HZ (i.e. 1000) in get_tbclk.  However, these
> two functions are expected to be used together, so they must be
> consistent in their return value.

actually there is no disagreement between us, i totally agree with you
that the return value of get_ticks() should be in CONFIG_SYS_HZ
resolution and consistent with get_tbclk(). the patch i sent you
yesterday off-list fixes exactly this.

> It's true that the functions are little used (they are mostly used in
> ppc code, within cpu/*/interrupts), and that's why I didn't even
> provide them in cpu/arm926ejs/nomadik/timer.c. All few users assume
> they are consistent, but there is no documentation:
> 
>      tornado% grep -qr get_tbclk README* doc  || echo not found
>      not found
>      tornado% grep -qr get_ticks README* doc/* || echo not found
>      not found
> 
> I've made a quick tour of all definitions in cpu/ and here is the result.
> As you see, at91 (which you used as reference, I understand) is wrong,
> while all the others use either hwticks or SYS_HZ consistently.

yes, i used precisely at91 as reference, i liked it's code structure
and didn't notice that it is wrong in this point.

thanks for your research!

-- 
Matthias Kaehlcke
Embedded Linux Developer
Barcelona

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