From b1b135c8d619cb2c7045d6ee4e48375882518bb5 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Thu, 7 Aug 2008 09:18:34 +0200 Subject: [PATCH] fix spinlock recursion in hvc_console commit 611e097d7707741a336a0677d9d69bec40f29f3d Author: Christian Borntraeger hvc_console: rework setup to replace irq functions with callbacks introduced a spinlock recursion problem. request_irq tries to call the handler if the IRQ is shared. The irq handler of hvc_console calls hvc_poll and hvc_kill which might take the hvc_struct spinlock. Therefore, we have to call request_irq outside the spinlock. We can move the notifier_add safely outside the spinlock as ->data must not be changed by the backend. Otherwise, tty_hangup would fail anyway. Signed-off-by: Christian Borntraeger Signed-off-by: Rusty Russell --- drivers/char/hvc_console.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c index 02aac104842d..fd64137b1ab9 100644 --- a/drivers/char/hvc_console.c +++ b/drivers/char/hvc_console.c @@ -322,11 +322,10 @@ static int hvc_open(struct tty_struct *tty, struct file * filp) hp->tty = tty; - if (hp->ops->notifier_add) - rc = hp->ops->notifier_add(hp, hp->data); - spin_unlock_irqrestore(&hp->lock, flags); + if (hp->ops->notifier_add) + rc = hp->ops->notifier_add(hp, hp->data); /* * If the notifier fails we return an error. The tty layer -- 2.20.1