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Date: Thu, 06 Feb 2003 09:41:48 -0800
From: Ross Biro <rossb@google.com>
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To: Alan Cox <alan@lxorguk.ukuu.org.uk>
CC: Ivan Kokshaysky <ink@jurassic.park.msu.ru>,
       Geert Uytterhoeven <geert@linux-m68k.org>,
       Linux Kernel Development <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] PATCH: add framework for ndelay (nanoseconds)
References: <200302040533.h145Xqq19457@hera.kernel.org>	 <Pine.GSO.4.21.0302051533320.16681-100000@vervain.sonytel.be>	 <20030206174944.A17905@jurassic.park.msu.ru> <1044546783.10374.4.camel@irongate.swansea.linux.org.uk>
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Alan Cox wrote:

>Why waste 500nS every IDE command as opposed to doing the job right ? The initial
>ndelay() is a quick implementation. If you don't like it implement a better one,
>if your box isnt fast implement it as udelay.
>  
>
The delay should be made controller specific.  On most controllers the 
reading of the alt status we need to do to flush the write command to 
the drive will also cause enough of a delay so that the ndelay isn't 
needed at all.  For example the on the Promise 20265 and 20267 the alt 
status read will always take at least 600ns.

    Ross

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