From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Roland" Subject: Re: [PATCH] mdacon messing up default vc's, set default to vc13-16 again Date: Mon, 5 May 2008 20:47:29 +0200 Message-ID: <00db01c8aee0$78e7bea0$6400a8c0@bui.materna.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1-new.sourceforge.net with esmtp (Exim 4.43) id 1Jt5j3-0002BB-Vo for Linux-fbdev-devel@lists.sourceforge.net; Mon, 05 May 2008 11:47:49 -0700 Received: from fmmailgate02.web.de ([217.72.192.227]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1Jt5j0-0008Ux-VO for Linux-fbdev-devel@lists.sourceforge.net; Mon, 05 May 2008 11:47:49 -0700 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-fbdev-devel-bounces@lists.sourceforge.net Errors-To: linux-fbdev-devel-bounces@lists.sourceforge.net To: Linux-fbdev-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Cc: Soeren Sonnenburg , jsimmons@infradead.org, adaplas@gmail.com, matan@svgalib.org, edward@debian.org, Andrew Morton , Alan Cox > mdacon incorrectly detects MDA hardware on systems without such graphics > card. > > one may load this module by chance, for example when doing some > systematical > module-testing, and if there is no Monochrome Display Adapter attached , > module init > renders vc1-16 completely unusable. > > me and others have run into this more than once. see [Bug 224522 - > modprobe mdacon > freezes machine -> https://bugzilla.novell.com/show_bug.cgi?id=224522 ] > for example or somebody may accidentally link it statically with the kernel.....and have some fun then.... http://marc.info/?l=linux-kernel&m=112550081223569&w=2 -> http://marc.info/?l=linux-kernel&m=112550983822140&w=2 > > apparently, proper MDA detection seems to be broken for a long time - > seems to be > related to those #ifdef TEST_MDA_B statements added by Edward Betts. > > this commit back in 2002 made things even worse : > http://git.kernel.org/?p=linux/kernel/git/tglx/history.git;a=commit;h=c72757b49c88914433244757fb4967fc63546685 > > it changed default vc allocation from 13-16 to 1-16 for no apparent > reason (!?) , and > with that (and without X), mdacon grabs the vc you`re currently sitting on > and locks you out. > > this is from Kconfig : > >config MDA_CONSOLE > > depends on !M68K && !PARISC && ISA > > tristate "MDA text console (dual-headed) (EXPERIMENTAL)" > > ---help--- > > Say Y here if you have an old MDA or monochrome Hercules > > graphics > > adapter in your system acting as a second head ( = video card). > > You > > will then be able to use two monitors with your Linux system. > > Do not > > say Y here if your MDA card is the primary card in your system; > > the > > normal VGA driver will handle it. > > As we can see mdacon is just meant as an additional driver for dual-head > setup, > and since kernel 2.4.36 still defaults to vc13-16 , setting the default > back to that value > again shouldn`t do any harm. > > hereby i`m reverting that change, setting default back to to vc13-16 > again. > > Besides the fact that mdacon may be rarely or never be used these days and > could > perhaps put to trash anyway (pre-dinosaur hardware!), indeed this is not a > real solution, > but at least it removes the unfortunate side-effect of messing up the vc > you`re working on. > > > Signed-off-by: Roland Kletzing > > --- drivers/video/console/mdacon.c.orig 2008-05-03 15:47:20.000000000 > +0200 > +++ drivers/video/console/mdacon.c 2008-05-03 15:55:27.000000000 > +0200 > @@ -71,13 +71,15 @@ > > /* console information */ > > -static int mda_first_vc = 1; > +static int mda_first_vc = 13; > static int mda_last_vc = 16; > > static struct vc_data *mda_display_fg = NULL; > > module_param(mda_first_vc, int, 0); > +MODULE_PARM_DESC(mda_first_vc, "First virtual console. Default: 13"); > module_param(mda_last_vc, int, 0); > +MODULE_PARM_DESC(mda_last_vc, "Last virtual console. Default: 16"); > > /* MDA register values > */ > ------------------------------------------------------------------------- This SF.net email is sponsored by the 2008 JavaOne(SM) Conference Don't miss this year's exciting event. There's still time to save $100. Use priority code J8TL2D2. http://ad.doubleclick.net/clk;198757673;13503038;p?http://java.sun.com/javaone