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Message-ID: <40F463B0.1010706@pobox.com>
Date: Tue, 13 Jul 2004 18:35:28 -0400
From: Jeff Garzik <jgarzik@pobox.com>
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To: Matt Domsch <Matt_Domsch@dell.com>
CC: David Balazic <david.balazic@hermes.si>, Dave Jones <davej@redhat.com>,
       Andries Brouwer <aebr@win.tue.nl>, Pavel Machek <pavel@suse.cz>,
       Linux Kernel <linux-kernel@vger.kernel.org>, Andi Kleen <ak@suse.de>,
       Andrew Morton <akpm@osdl.org>
Subject: Re: Weird:  30 sec delay during early boot
References: <600B91D5E4B8D211A58C00902724252C035F1D0C@piramida.hermes.si> <20040713221623.GA10480@lists.us.dell.com>
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Matt Domsch wrote:
> David, Jeff, would you mind trying the patch below on your systems
> which exhibit the long delays in the EDD real-mode code?
> 
> This does a few things:
> 1) it uses an int13 fn15 "Get Disk Type" command prior to doing the
> fn02 "Read Sectors" command, to try to determine if there is a disk
> present or not before reading its signature.
> 
> 2) A few registers are more fully zeroed out, in case the BIOS cared
> about things it shouldn't have.
> 
> Crossing my fingers that the delays are gone...

Can you attach the patch, or switch mailers?

The patch is word-wrapped and otherwise munged :(

Example:
> +# Do int13 fn15 first, as BIOS should know if a disk is present or not.
> +# This avoids long (>30s) delays waiting for the READ_SECTORS to a non-pre=
> sent disk.
> +       xor     %eax, %eax