Commit f70c81d4 authored by Pat Gefre's avatar Pat Gefre Committed by Linus Torvalds
Browse files

[PATCH] 2.6 Altix: console fix for CONFIG_DEBUG_SHIRQ usage 



The sn console driver was snagged by the use of CONFIG_DEBUG_SHIRQ!

The request_irq() immediate call to the interrupt handler caused
another attempt to lock the port lock - deadlock.

This is a patch to fix that.

Signed-off-by: default avatarPatrick Gefre <pfg@sgi.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 44f5c4ce

drivers/serial/sn_console.c

+17 −35
Original line number Diff line number Diff line
@@ -635,25 +635,6 @@ static irqreturn_t sn_sal_interrupt(int irq, void *dev_id) 
	return IRQ_HANDLED;

}



/**

 * sn_sal_connect_interrupt - Request interrupt, handled by sn_sal_interrupt

 * @port: Our sn_cons_port (which contains the uart port)

 *

 * returns the console irq if interrupt is successfully registered, else 0

 *

 */

static int sn_sal_connect_interrupt(struct sn_cons_port *port)

{

	if (request_irq(SGI_UART_VECTOR, sn_sal_interrupt,

			IRQF_DISABLED | IRQF_SHARED,

			"SAL console driver", port) >= 0) {

		return SGI_UART_VECTOR;

	}



	printk(KERN_INFO "sn_console: console proceeding in polled mode\n");

	return 0;

}



/**

 * sn_sal_timer_poll - this function handles polled console mode

 * @data: A pointer to our sn_cons_port (which contains the uart port)
@@ -746,31 +727,32 @@ static void __init sn_sal_switch_to_asynch(struct sn_cons_port *port) 
 * mode.  We were previously in asynch/polling mode (using init_timer).

 *

 * We attempt to switch to interrupt mode here by calling

 * sn_sal_connect_interrupt.  If that works out, we enable receive interrupts.

 * request_irq.  If that works out, we enable receive interrupts.

 */

static void __init sn_sal_switch_to_interrupts(struct sn_cons_port *port)

{

	int irq;

	unsigned long flags;



	if (!port)

		return;



	if (port) {

		DPRINTF("sn_console: switching to interrupt driven console\n");



		if (request_irq(SGI_UART_VECTOR, sn_sal_interrupt,

				IRQF_DISABLED | IRQF_SHARED,

				"SAL console driver", port) >= 0) {

			spin_lock_irqsave(&port->sc_port.lock, flags);



	irq = sn_sal_connect_interrupt(port);



	if (irq) {

		port->sc_port.irq = irq;

			port->sc_port.irq = SGI_UART_VECTOR;

			port->sc_ops = &intr_ops;



			/* turn on receive interrupts */

			ia64_sn_console_intr_enable(SAL_CONSOLE_INTR_RECV);

	}

			spin_unlock_irqrestore(&port->sc_port.lock, flags);

		}

		else {

			printk(KERN_INFO

			    "sn_console: console proceeding in polled mode\n");

		}

	}

}



/*

 * Kernel console definitions

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