Subject: tty/serial/pl011: Make the locking work on RT
From: Thomas Gleixner <tglx@linutronix.de>
Date: Tue Jan  8 21:36:51 2013 +0100
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz

From: Thomas Gleixner <tglx@linutronix.de>

The lock is a sleeping lock and local_irq_save() is not the optimsation
we are looking for. Redo it to make it work on -RT and non-RT.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>


---
 drivers/tty/serial/amba-pl011.c |   12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)
---
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2332,13 +2332,10 @@ pl011_console_write(struct console *co,
 
 	clk_enable(uap->clk);
 
-	local_irq_save(flags);
-	if (uap->port.sysrq)
-		locked = 0;
-	else if (oops_in_progress)
-		locked = uart_port_trylock(&uap->port);
+	if (uap->port.sysrq || oops_in_progress)
+		locked = uart_port_trylock_irqsave(&uap->port, &flags);
 	else
-		uart_port_lock(&uap->port);
+		uart_port_lock_irqsave(&uap->port, &flags);
 
 	/*
 	 *	First save the CR then disable the interrupts
@@ -2364,8 +2361,7 @@ pl011_console_write(struct console *co,
 		pl011_write(old_cr, uap, REG_CR);
 
 	if (locked)
-		uart_port_unlock(&uap->port);
-	local_irq_restore(flags);
+		uart_port_unlock_irqrestore(&uap->port, flags);
 
 	clk_disable(uap->clk);
 }
