The patch titled
mdacon messing up default vc's - set default to vc13-16 again
has been added to the -mm tree. Its filename is
mdacon-messing-up-default-vcs-set-default-to-vc13-16-again.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: mdacon messing up default vc's - set default to vc13-16 again
From: Roland Kletzing <devzero@xxxxxx>
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.
I 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
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 <devzero@xxxxxx>
Cc: James Simmons <jsimmons@xxxxxxxxxxxxx>
Cc: "Antonino A. Daplas" <adaplas@xxxxxxx>
Cc: Tim Schmielau <tim@xxxxxxxxxxxxxxxxxxxxxx>
Cc: Jan Engelhardt <jengelh@xxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/video/console/mdacon.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff -puN drivers/video/console/mdacon.c~mdacon-messing-up-default-vcs-set-default-to-vc13-16-again drivers/video/console/mdacon.c
--- a/drivers/video/console/mdacon.c~mdacon-messing-up-default-vcs-set-default-to-vc13-16-again
+++ a/drivers/video/console/mdacon.c
@@ -71,13 +71,15 @@ static char *mda_type_name;
/* 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
*/
_
Patches currently in -mm which might be from devzero@xxxxxx are
linux-next.patch
mdacon-messing-up-default-vcs-set-default-to-vc13-16-again.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
