Re: [Linux-fbdev-devel] [PATCH] nvidiafb: allow ignoring EDID info

From: Luca Tettamanti <kronos@people.it>
To: linux-fbdev-devel@lists.sourceforge.net
Cc: Andrew Morton <akpm@osdl.org>, Dave Airlie <airlied@gmail.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [Linux-fbdev-devel] [PATCH] nvidiafb: allow ignoring EDID info
Date: Thu, 8 Feb 2007 00:57:28 +0100	[thread overview]
Message-ID: <20070207235728.GA28695@dreamland.darkstar.lan> (raw)
In-Reply-To: <cb7bb73a0702051328n50c889d9o461ac2bb9f9ea75e@mail.gmail.com>

Il Mon, Feb 05, 2007 at 10:28:36PM +0100, Giuseppe Bilotta ha scritto: 
> On 2/5/07, Luca Tettamanti <kronos@people.it> wrote:
> > get-edid uses the BIOS, while the other two talk directly over the I2C
> > bus.
> >
> > Try loading i2c-dev (I2C_CHARDEV); With i2cdump[1] you can read the EDID
> > block, which resides at address 0x50:
> >
> > i2cdump N 0x50 (where N is the bus number)
> >
> > If you are unshure about bus number try with all the available
> > /dev/i2c-* devices (you may want to unload HW monitor drivers first, so
> > you don't poke at random stuff).
[...]
> There is no such thing as /dev/i2c* UNLESS I load nvidiafb.

Of course :)

> When I
> load that, I get three busses (i2c-0, -1, and -2), but i2cdump N 0x50
> gives me a nice tableau of X's all around, for all values of N.

There may be a bug in the serial clock line control, at least the code
looks strange. I'll check and come back with a patch ASAP.

Luca
-- 
"Sei l'unica donna della mia vita".
(Adamo)