linux-kernel - Re: Weird Xorg stretching (setfont)

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Message-ID:  <g0kal5$f5v$1@ger.gmane.org>
Date:	Fri, 16 May 2008 16:53:08 +0100
From:	Sitsofe Wheeler <sitsofe@...oo.com>
To:	linux-kernel@...r.kernel.org
Subject:  Re: Weird Xorg stretching (setfont)

Dave Airlie wrote:

> wierd got any fglrx or anything installed on you're system.. the
> radeon drm hasn't seen any changes that should affect this sorta
> thing, do you run radeonfb or vesafb?

Just in case you didn't see my reply I'm not an fglrx user and I don't run
radeonfb or vesafb.

After testing far too many kernels it turns out that this is not a
conventional regression. During startup openSUSE runs the following
command:

/bin/setfont -C /dev/tty1 lat9w-16.psfu -m trivial

in /etc/init.d/kbd

Now on the openSUSE provided 2.6.22.17-0.1-default #1 SMP kernel if X has
started and your run that command (e.g.
chvt 7; sleep 5s && /bin/setfont -C /dev/tty1 lat9w-16.psfu -m trivial
) the command will fail with error output similar to the following:
setfont: putfont: 256,8x16: failed: -1
putfont: KDFONTOP: Invalid Argument

If you are using a stock kernel (e.g. 2.6.24/2.6.25 etc) the command will
not fail and will instead corrupt X causing the lower part of the screen to
be drawn using the same line (creating a stretch/mirror effect).

There seems to be a bit of mention of this over in
https://bugzilla.novell.com/show_bug.cgi?id=335267 but that talks about it
failing (which I consider to be better behaviour than corrupting X).

The whole thing is racy on boot (e.g. if setfont happens before X is shown
then there is no corruption) fooling me into thinking it was a regression.

-- 
Sitsofe

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