Commit 31555213 authored Nov 06, 2011 by Linus Torvalds

Revert "hvc_console: display printk messages on console."



This reverts commit 36116245.

It causes an infinite loop when booting Linux under Xen, as so:

  [    2.382984] console [hvc0] enabled
  [    2.382984] console [hvc0] enabled
  [    2.382984] console [hvc0] enabled
  ...

as reported by Konrad Rzeszutek Wilk.  And Rusty reports the same for
lguest.  He goes on to say:

   "This is not a concurrency problem: the issue seems to be that
    calling register_console() twice on the same struct console is a bad
    idea."

and Greg says he'll fix it up properly at some point later. Revert for now.

Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reported-by: Rusty Russell <rusty@ozlabs.org>
Requested-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Miche Baker-Harvey <miche@google.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 0084e475

drivers/tty/hvc/hvc_console.c

+1 −6

Original line number	Original line	Diff line number	Diff line
	@@ -862,13 +862,9 @@ struct hvc_struct *hvc_alloc(uint32_t vtermno, int data,
	i = ++last_hvc;		i = ++last_hvc;

	hp->index = i;		hp->index = i;
	hvc_console.index = i;
	vtermnos[i] = vtermno;
	cons_ops[i] = ops;

	list_add_tail(&(hp->next), &hvc_structs);		list_add_tail(&(hp->next), &hvc_structs);
	spin_unlock(&hvc_structs_lock);		spin_unlock(&hvc_structs_lock);
	register_console(&hvc_console);

	return hp;		return hp;
	}		}
	@@ -879,7 +875,6 @@ int hvc_remove(struct hvc_struct *hp)
	unsigned long flags;		unsigned long flags;
	struct tty_struct *tty;		struct tty_struct *tty;

	unregister_console(&hvc_console);
	spin_lock_irqsave(&hp->lock, flags);		spin_lock_irqsave(&hp->lock, flags);
	tty = tty_kref_get(hp->tty);		tty = tty_kref_get(hp->tty);