[001/244] kernel/printk: do not turn off bootconsole in printk_late_init() if keep_bootcon

[Greg KH]

3.0-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Nishanth Aravamudan <nacc@xxxxxxxxxx>

commit 4c30c6f566c0989ddaee3407da44751e340a63ed upstream.

It seems that 7bf693951a8e ("console: allow to retain boot console via
boot option keep_bootcon") doesn't always achieve what it aims, as when
printk_late_init() runs it unconditionally turns off all boot consoles.
With this patch, I am able to see more messages on the boot console in
KVM guests than I can without, when keep_bootcon is specified.

I think it is appropriate for the relevant -stable trees.  However, it's
more of an annoyance than a serious bug (ideally you don't need to keep
the boot console around as console handover should be working -- I was
encountering a situation where the console handover wasn't working and
not having the boot console available meant I couldn't see why).

Signed-off-by: Nishanth Aravamudan <nacc@xxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Cc: Greg KH <gregkh@xxxxxxx>
Acked-by: Fabio M. Di Nitto <fdinitto@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 kernel/printk.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1584,7 +1584,7 @@ static int __init printk_late_init(void)
 	struct console *con;
 
 	for_each_console(con) {
-		if (con->flags & CON_BOOT) {
+		if (!keep_bootcon && con->flags & CON_BOOT) {
 			printk(KERN_INFO "turn off boot console %s%d\n",
 				con->name, con->index);
 			unregister_console(con);


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