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Message-ID: <4BFAA3FA.6080906@aldan.algebra.com>
Date: Mon, 24 May 2010 12:06:18 -0400
From: "Mikhail T." <mi+thun@aldan.algebra.com>
Organization: Virtual Estates, Inc.
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To: Kostik Belousov <kostikbel@gmail.com>
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Cc: acpi@freebsd.org, danfe@freebsd.org, linux@freebsd.org
Subject: Re: Extracting screen's EDID-information from ACPI
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22.05.2010 12:59, Kostik Belousov ΞΑΠΙΣΑΧ(ΜΑ):
> My hybrid  (Z820) only provides EDID information when switched to
> use intel graphics. Nvidia driver reports that no screens are attached.
>    
Exactly... For some reason NVidia driver fails to detect the screen and 
is not smart enough obtain the information via ACPI itself.

The work-around is to extract the EDID from ACPI manually and make it 
available to the driver as file (128-bytes long).

I managed to extract that information from the result of `acpidump -o 
dump' -- by writing a little program to look for the proper 
byte-sequence (gleaned from the sources of 
http://www.polypux.org/projects/read-edid/)...

I may polish my utility and publish it, but things should be easier than 
that -- as, dare I say it, they already is under Linux, for example 
(with their /proc/acpi/... )

    -mi