Re: 2.6.18-rt1

[Ingo Molnar <mingo@elte.hu>]

* Daniel Walker <dwalker@mvista.com> wrote:

> On Wed, 2006-09-20 at 22:14 +0200, Ingo Molnar wrote:
> > >         if (up->port.sysrq) {
> > >                 /* serial8250_handle_port() already took the lock */
> > >                 locked = 0;
> 
> 
> In this case it had interrupts off in the !PREEMPT_RT case, but your 
> change leaves them on here.. _irqsave only runs in two of the three 
> cases..

doh, right you are. I updated to the patch below.

	Ingo

Index: linux/drivers/serial/8250.c
===================================================================
--- linux.orig/drivers/serial/8250.c
+++ linux/drivers/serial/8250.c
@@ -2252,14 +2252,10 @@ serial8250_console_write(struct console 
 
 	touch_nmi_watchdog();
 
-	local_irq_save(flags);
-	if (up->port.sysrq) {
-		/* serial8250_handle_port() already took the lock */
-		locked = 0;
-	} else if (oops_in_progress) {
-		locked = spin_trylock(&up->port.lock);
-	} else
-		spin_lock(&up->port.lock);
+	if (up->port.sysrq || oops_in_progress)
+		locked = spin_trylock_irqsave(&up->port.lock, flags);
+	else
+		spin_lock_irqsave(&up->port.lock, flags);
 
 	/*
 	 *	First save the IER then disable the interrupts
@@ -2281,8 +2277,7 @@ serial8250_console_write(struct console 
 	serial_out(up, UART_IER, ier);
 
 	if (locked)
-		spin_unlock(&up->port.lock);
-	local_irq_restore(flags);
+		spin_unlock_irqrestore(&up->port.lock, flags);
 }
 
 static int serial8250_console_setup(struct console *co, char *options)