diff options
Diffstat (limited to 'drivers/s390/char/sclp_vt220.c')
| -rw-r--r-- | drivers/s390/char/sclp_vt220.c | 42 |
1 files changed, 23 insertions, 19 deletions
diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c index 3b4e7e5d9b71..a32f34a1c6d2 100644 --- a/drivers/s390/char/sclp_vt220.c +++ b/drivers/s390/char/sclp_vt220.c @@ -769,21 +769,6 @@ __initcall(sclp_vt220_tty_init); #ifdef CONFIG_SCLP_VT220_CONSOLE -static void __sclp_vt220_flush_buffer(void) -{ - unsigned long flags; - - sclp_vt220_emit_current(); - spin_lock_irqsave(&sclp_vt220_lock, flags); - del_timer(&sclp_vt220_timer); - while (sclp_vt220_queue_running) { - spin_unlock_irqrestore(&sclp_vt220_lock, flags); - sclp_sync_wait(); - spin_lock_irqsave(&sclp_vt220_lock, flags); - } - spin_unlock_irqrestore(&sclp_vt220_lock, flags); -} - static void sclp_vt220_con_write(struct console *con, const char *buf, unsigned int count) { @@ -797,22 +782,41 @@ sclp_vt220_con_device(struct console *c, int *index) return sclp_vt220_driver; } +/* + * This panic/reboot notifier runs in atomic context, so + * locking restrictions apply to prevent potential lockups. + */ static int sclp_vt220_notify(struct notifier_block *self, unsigned long event, void *data) { - __sclp_vt220_flush_buffer(); - return NOTIFY_OK; + unsigned long flags; + + if (spin_is_locked(&sclp_vt220_lock)) + return NOTIFY_DONE; + + sclp_vt220_emit_current(); + + spin_lock_irqsave(&sclp_vt220_lock, flags); + del_timer(&sclp_vt220_timer); + while (sclp_vt220_queue_running) { + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + sclp_sync_wait(); + spin_lock_irqsave(&sclp_vt220_lock, flags); + } + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + + return NOTIFY_DONE; } static struct notifier_block on_panic_nb = { .notifier_call = sclp_vt220_notify, - .priority = 1, + .priority = INT_MIN + 1, /* run the callback late */ }; static struct notifier_block on_reboot_nb = { .notifier_call = sclp_vt220_notify, - .priority = 1, + .priority = INT_MIN + 1, /* run the callback late */ }; /* Structure needed to register with printk */ |