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Re: mdelay() from board_setup() [is default value for loops_per_jiffy wa

To: Pete Popov <ppopov@embeddedalley.com>
Subject: Re: mdelay() from board_setup() [is default value for loops_per_jiffy way off?]
From: Ralf Baechle <ralf@linux-mips.org>
Date: Wed, 20 Apr 2005 19:07:20 +0100
Cc: Clem Taylor <clem.taylor@gmail.com>, linux-mips@linux-mips.org
In-reply-to: <42669862.7000405@embeddedalley.com>
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On Wed, Apr 20, 2005 at 10:58:58AM -0700, Pete Popov wrote:

> It's too early in board_setup() to use the standard delay routines. You 
> can't use those until after calibrate_delay() runs. To do precise delays in 
> board_setup, you'll have to do something yourself where you read the cp0 
> timer periodically and wait a certain amount of time.

And make sure not to be trapped by wrap-arounds of that counter.  Also it
doesn't count the same speed on all processors ...

  Ralf

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