When CONFIG_PM is enabled, it uses the TOY_MATCH2 interrupt as the system

timer tick. Prior to this patch, if IDE IRQ probing occured, then the
TOY_MATCH2 interrupt would be permanently disabled, and no system timer
tick occurs. This patch corrects this situation by correctly registering
the TOY_MATCH2 interrupt so that IDE IRQ probing doesn't have adverse
side effects.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/au1000/common/irq.c

@@ -293,8 +293,30 @@ static struct hw_interrupt_type level_irq_type = {
 };
 
 #ifdef CONFIG_PM
-void startup_match20_interrupt(void)
+void startup_match20_interrupt(void (*handler)(int, void *, struct pt_regs *))
 {
+	static struct irqaction action;
+	/* This is a big problem.... since we didn't use request_irq
+	   when kernel/irq.c calls probe_irq_xxx this interrupt will
+	   be probed for usage. This will end up disabling the device :(
+
+       Give it a bogus "action" pointer -- this will keep it from
+	   getting auto-probed!
+
+       By setting the status to match that of request_irq() we
+       can avoid it.  --cgray
+	*/
+	action.dev_id = handler;
+	action.flags = 0;
+	action.mask = 0;
+	action.name = "Au1xxx TOY";
+	action.handler = handler;
+	action.next = NULL;
+
+	irq_desc[AU1000_TOY_MATCH2_INT].action = &action; 
+	irq_desc[AU1000_TOY_MATCH2_INT].status 
+		 &= ~(IRQ_DISABLED | IRQ_AUTODETECT | IRQ_WAITING | IRQ_INPROGRESS);
+
 	local_enable_irq(AU1000_TOY_MATCH2_INT);
 }
 #endif
@@ -517,17 +539,7 @@ void intc0_req1_irqdispatch(struct pt_regs *regs)
 
 	irq = au_ffs(intc0_req1) - 1;
 	intc0_req1 &= ~(1<<irq);
-#ifdef CONFIG_PM
-	if (irq == AU1000_TOY_MATCH2_INT) {
-		mask_and_ack_rise_edge_irq(irq);
-		counter0_irq(irq, NULL, regs);
-		local_enable_irq(irq);
-	}
-	else
-#endif
-	{
-		do_IRQ(irq, regs);
-	}
+	do_IRQ(irq, regs);
 }
 
 

arch/mips/au1000/common/time.c

@@ -50,7 +50,6 @@
 #include <linux/mc146818rtc.h>
 #include <linux/timex.h>
 
-extern void startup_match20_interrupt(void);
 extern void do_softirq(void);
 extern volatile unsigned long wall_jiffies;
 unsigned long missed_heart_beats = 0;
@@ -65,7 +64,7 @@ static unsigned int timerhi = 0, timerlo = 0;
 
 #ifdef CONFIG_PM
 #define MATCH20_INC 328
-extern void startup_match20_interrupt(void);
+extern void startup_match20_interrupt(void (*handler)(int, void *, struct pt_regs *));
 static unsigned long last_pc0, last_match20;
 #endif
 
@@ -446,7 +445,7 @@ void au1xxx_timer_setup(struct irqaction *irq)
 		au_writel(last_match20 + MATCH20_INC, SYS_TOYMATCH2);
 		au_sync();
 		while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20);
-		startup_match20_interrupt();
+		startup_match20_interrupt(counter0_irq);
 
 		do_gettimeoffset = do_fast_pm_gettimeoffset;