drivers-serial-call-flush_to_ldisc-when-the-irq-is-t.patch

From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 3 Jul 2009 08:30:01 -0500
Subject: serial: 8250: Call flush_to_ldisc when the irq is threaded

Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
 drivers/tty/serial/8250/8250.c |    2 ++
 drivers/tty/tty_buffer.c       |    4 ++++
 2 files changed, 6 insertions(+)

Index: linux-stable/drivers/tty/serial/8250/8250.c
===================================================================
--- linux-stable.orig/drivers/tty/serial/8250/8250.c
+++ linux-stable/drivers/tty/serial/8250/8250.c
@@ -1549,12 +1549,14 @@ static irqreturn_t serial8250_interrupt(
 
 		l = l->next;
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 		if (l == i->head && pass_counter++ > PASS_LIMIT) {
 			/* If we hit this, we're dead. */
 			printk_ratelimited(KERN_ERR
 				"serial8250: too much work for irq%d\n", irq);
 			break;
 		}
+#endif
 	} while (l != end);
 
 	spin_unlock(&i->lock);
Index: linux-stable/drivers/tty/tty_buffer.c
===================================================================
--- linux-stable.orig/drivers/tty/tty_buffer.c
+++ linux-stable/drivers/tty/tty_buffer.c
@@ -538,10 +538,14 @@ void tty_flip_buffer_push(struct tty_str
 		tty->buf.tail->commit = tty->buf.tail->used;
 	spin_unlock_irqrestore(&tty->buf.lock, flags);
 
+#ifndef CONFIG_PREEMPT_RT_FULL
 	if (tty->low_latency)
 		flush_to_ldisc(&tty->buf.work);
 	else
 		schedule_work(&tty->buf.work);
+#else
+	flush_to_ldisc(&tty->buf.work);
+#endif
 }
 EXPORT_SYMBOL(tty_flip_buffer_push);