diff options
Diffstat (limited to 'drivers/s390/char/sclp_con.c')
| -rw-r--r-- | drivers/s390/char/sclp_con.c | 26 |
1 files changed, 15 insertions, 11 deletions
diff --git a/drivers/s390/char/sclp_con.c b/drivers/s390/char/sclp_con.c index fe5ee2646fcf..e5d947c763ea 100644 --- a/drivers/s390/char/sclp_con.c +++ b/drivers/s390/char/sclp_con.c @@ -220,30 +220,34 @@ sclp_console_device(struct console *c, int *index) } /* - * Make sure that all buffers will be flushed to the SCLP. + * This panic/reboot notifier makes sure that all buffers + * will be flushed to the SCLP. */ -static void -sclp_console_flush(void) +static int sclp_console_notify(struct notifier_block *self, + unsigned long event, void *data) { + /* + * Perform the lock check before effectively getting the + * lock on sclp_conbuf_emit() / sclp_console_sync_queue() + * to prevent potential lockups in atomic context. + */ + if (spin_is_locked(&sclp_con_lock)) + return NOTIFY_DONE; + sclp_conbuf_emit(); sclp_console_sync_queue(); -} -static int sclp_console_notify(struct notifier_block *self, - unsigned long event, void *data) -{ - sclp_console_flush(); - return NOTIFY_OK; + return NOTIFY_DONE; } static struct notifier_block on_panic_nb = { .notifier_call = sclp_console_notify, - .priority = 1, + .priority = INT_MIN + 1, /* run the callback late */ }; static struct notifier_block on_reboot_nb = { .notifier_call = sclp_console_notify, - .priority = 1, + .priority = INT_MIN + 1, /* run the callback late */ }; /* |