From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jeff Garzik <jeff@garzik.org>
Subject: Re: 2.6.18-rc1-mm1
Date: Sun, 09 Jul 2006 12:29:10 -0400
Message-ID: <44B12ED6.10000@garzik.org>
References: <20060709021106.9310d4d1.akpm@osdl.org>	 <44B0E6E6.6070904@reub.net>  <20060709052252.8c95202a.akpm@osdl.org> <1152449805.27368.57.camel@localhost.localdomain>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Return-path: <linux-ide-owner@vger.kernel.org>
Received: from srv5.dvmed.net ([207.36.208.214]:185 "EHLO mail.dvmed.net")
	by vger.kernel.org with ESMTP id S1751323AbWGIQ30 (ORCPT
	<rfc822;linux-ide@vger.kernel.org>); Sun, 9 Jul 2006 12:29:26 -0400
In-Reply-To: <1152449805.27368.57.camel@localhost.localdomain>
Sender: linux-ide-owner@vger.kernel.org
List-Id: linux-ide@vger.kernel.org
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Andrew Morton <akpm@osdl.org>, Reuben Farrelly <reuben-lkml@reub.net>, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, rdunlap@xenotime.net, greg@kroah.com, john stultz <johnstul@us.ibm.com>, Andi Kleen <ak@muc.de>, "linux-ide@vger.kernel.org" <linux-ide@vger.kernel.org>

Alan Cox wrote:
> The old drivers/ide code uses much longer delays than the spec for some
> ATAPI commands, and it looks as if there is a good reason for doing
> so ...


FWIW, the code that ATADRVR (http://www.ata-atapi.com/) uses to issue 
commands does something like

	write Command register to start command
	if (device == ATAPI)			# i.e. not ATA
		delay(150 msec)
	pound Status / AltStatus, kick DMA engine, whatever else

ATADRVR is open code (for an MS-DOS-level driver), and really worth a 
read.  Between ATADRVR and drivers/ide, you get a pretty good idea about 
what __field experience__ has shown is needed for ATAPI devices.

	Jeff