MIPS: Alchemy: Remove USB_DEV_REQ_INT prioritization hack

The Alchemy hardware provides a method to prioritize interrupts
on a controller by assigning them to a differenct core request line.
Assign usb device request interrupt to IC0 Request 0 (which has
highest priority in the core and the dispatcher) and others to
Request 1.  The explicit check for usb device request occurrence
should be obsolete now.

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/alchemy/common/irq.c

@@ -39,11 +39,18 @@
 
 static int au1x_ic_settype(unsigned int irq, unsigned int flow_type);
 
+/* NOTE on interrupt priorities: The original writers of this code said:
+ *
+ * Because of the tight timing of SETUP token to reply transactions,
+ * the USB devices-side packet complete interrupt (USB_DEV_REQ_INT)
+ * needs the highest priority.
+ */
+
 /* per-processor fixed function irqs */
 struct au1xxx_irqmap {
 	int im_irq;
 	int im_type;
-	int im_request;
+	int im_request;		/* set 1 to get higher priority */
 } au1xxx_ic0_map[] __initdata = {
 #if defined(CONFIG_SOC_AU1000)
 	{ AU1000_UART0_INT, IRQ_TYPE_LEVEL_HIGH, 0 },
@@ -63,14 +70,14 @@ struct au1xxx_irqmap {
 	{ AU1000_TOY_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_TOY_MATCH0_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_TOY_MATCH1_INT, IRQ_TYPE_EDGE_RISING, 0 },
-	{ AU1000_TOY_MATCH2_INT, IRQ_TYPE_EDGE_RISING, 1 },
+	{ AU1000_TOY_MATCH2_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_MATCH0_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_MATCH1_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_MATCH2_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_IRDA_TX_INT, IRQ_TYPE_LEVEL_HIGH, 0 },
 	{ AU1000_IRDA_RX_INT, IRQ_TYPE_LEVEL_HIGH, 0 },
-	{ AU1000_USB_DEV_REQ_INT, IRQ_TYPE_LEVEL_HIGH, 0 },
+	{ AU1000_USB_DEV_REQ_INT, IRQ_TYPE_LEVEL_HIGH, 1 },
 	{ AU1000_USB_DEV_SUS_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_USB_HOST_INT, IRQ_TYPE_LEVEL_LOW, 0 },
 	{ AU1000_ACSYNC_INT, IRQ_TYPE_EDGE_RISING, 0 },
@@ -97,12 +104,12 @@ struct au1xxx_irqmap {
 	{ AU1000_TOY_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_TOY_MATCH0_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_TOY_MATCH1_INT, IRQ_TYPE_EDGE_RISING, 0 },
-	{ AU1000_TOY_MATCH2_INT, IRQ_TYPE_EDGE_RISING, 1 },
+	{ AU1000_TOY_MATCH2_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_MATCH0_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_MATCH1_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_MATCH2_INT, IRQ_TYPE_EDGE_RISING, 0 },
-	{ AU1000_USB_DEV_REQ_INT, IRQ_TYPE_LEVEL_HIGH, 0 },
+	{ AU1000_USB_DEV_REQ_INT, IRQ_TYPE_LEVEL_HIGH, 1 },
 	{ AU1000_USB_DEV_SUS_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_USB_HOST_INT, IRQ_TYPE_LEVEL_LOW, 0 },
 	{ AU1000_ACSYNC_INT, IRQ_TYPE_EDGE_RISING, 0 },
@@ -129,14 +136,14 @@ struct au1xxx_irqmap {
 	{ AU1000_TOY_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_TOY_MATCH0_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_TOY_MATCH1_INT, IRQ_TYPE_EDGE_RISING, 0 },
-	{ AU1000_TOY_MATCH2_INT, IRQ_TYPE_EDGE_RISING, 1 },
+	{ AU1000_TOY_MATCH2_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_MATCH0_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_MATCH1_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_MATCH2_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_IRDA_TX_INT, IRQ_TYPE_LEVEL_HIGH, 0 },
 	{ AU1000_IRDA_RX_INT, IRQ_TYPE_LEVEL_HIGH, 0 },
-	{ AU1000_USB_DEV_REQ_INT, IRQ_TYPE_LEVEL_HIGH, 0 },
+	{ AU1000_USB_DEV_REQ_INT, IRQ_TYPE_LEVEL_HIGH, 1 },
 	{ AU1000_USB_DEV_SUS_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_USB_HOST_INT, IRQ_TYPE_LEVEL_LOW, 0 },
 	{ AU1000_ACSYNC_INT, IRQ_TYPE_EDGE_RISING, 0 },
@@ -163,13 +170,13 @@ struct au1xxx_irqmap {
 	{ AU1000_TOY_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_TOY_MATCH0_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_TOY_MATCH1_INT, IRQ_TYPE_EDGE_RISING, 0 },
-	{ AU1000_TOY_MATCH2_INT, IRQ_TYPE_EDGE_RISING, 1 },
+	{ AU1000_TOY_MATCH2_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_MATCH0_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_MATCH1_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_MATCH2_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1550_NAND_INT, IRQ_TYPE_EDGE_RISING, 0 },
-	{ AU1550_USB_DEV_REQ_INT, IRQ_TYPE_LEVEL_HIGH, 0 },
+	{ AU1550_USB_DEV_REQ_INT, IRQ_TYPE_LEVEL_HIGH, 1 },
 	{ AU1550_USB_DEV_SUS_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1550_USB_HOST_INT, IRQ_TYPE_LEVEL_LOW, 0 },
 	{ AU1550_MAC0_DMA_INT, IRQ_TYPE_LEVEL_HIGH, 0 },
@@ -191,7 +198,7 @@ struct au1xxx_irqmap {
 	{ AU1000_TOY_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_TOY_MATCH0_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_TOY_MATCH1_INT, IRQ_TYPE_EDGE_RISING, 0 },
-	{ AU1000_TOY_MATCH2_INT, IRQ_TYPE_EDGE_RISING, 1 },
+	{ AU1000_TOY_MATCH2_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_MATCH0_INT, IRQ_TYPE_EDGE_RISING, 0 },
 	{ AU1000_RTC_MATCH1_INT, IRQ_TYPE_EDGE_RISING, 0 },
@@ -507,7 +514,7 @@ static int au1x_ic_settype(unsigned int irq, unsigned int flow_type)
 asmlinkage void plat_irq_dispatch(void)
 {
 	unsigned int pending = read_c0_status() & read_c0_cause();
-	unsigned long s, off, bit;
+	unsigned long s, off;
 
 	if (pending & CAUSEF_IP7) {
 		do_IRQ(MIPS_CPU_IRQ_BASE + 7);
@@ -527,25 +534,12 @@ asmlinkage void plat_irq_dispatch(void)
 	} else
 		goto spurious;
 
-	bit = 0;
 	s = au_readl(s);
 	if (unlikely(!s)) {
 spurious:
 		spurious_interrupt();
 		return;
 	}
-#ifdef AU1000_USB_DEV_REQ_INT
-	/*
-	 * Because of the tight timing of SETUP token to reply
-	 * transactions, the USB devices-side packet complete
-	 * interrupt needs the highest priority.
-	 */
-	bit = 1 << (AU1000_USB_DEV_REQ_INT - AU1000_INTC0_INT_BASE);
-	if ((pending & CAUSEF_IP2) && (s & bit)) {
-		do_IRQ(AU1000_USB_DEV_REQ_INT);
-		return;
-	}
-#endif
 	do_IRQ(__ffs(s) + off);
 }
 
@@ -566,11 +560,11 @@ static void __init setup_irqmap(struct au1xxx_irqmap *map, int count)
 		if (irq_nr >= AU1000_INTC1_INT_BASE) {
 			bit = irq_nr - AU1000_INTC1_INT_BASE;
 			if (map[count].im_request)
-				au_writel(1 << bit, IC1_ASSIGNCLR);
+				au_writel(1 << bit, IC1_ASSIGNSET);
 		} else {
 			bit = irq_nr - AU1000_INTC0_INT_BASE;
 			if (map[count].im_request)
-				au_writel(1 << bit, IC0_ASSIGNCLR);
+				au_writel(1 << bit, IC0_ASSIGNSET);
 		}
 
 		au1x_ic_settype(irq_nr, map[count].im_type);
@@ -588,7 +582,7 @@ void __init arch_init_irq(void)
 	au_writel(0xffffffff, IC0_CFG1CLR);
 	au_writel(0xffffffff, IC0_CFG2CLR);
 	au_writel(0xffffffff, IC0_MASKCLR);
-	au_writel(0xffffffff, IC0_ASSIGNSET);
+	au_writel(0xffffffff, IC0_ASSIGNCLR);
 	au_writel(0xffffffff, IC0_WAKECLR);
 	au_writel(0xffffffff, IC0_SRCSET);
 	au_writel(0xffffffff, IC0_FALLINGCLR);
@@ -599,7 +593,7 @@ void __init arch_init_irq(void)
 	au_writel(0xffffffff, IC1_CFG1CLR);
 	au_writel(0xffffffff, IC1_CFG2CLR);
 	au_writel(0xffffffff, IC1_MASKCLR);
-	au_writel(0xffffffff, IC1_ASSIGNSET);
+	au_writel(0xffffffff, IC1_ASSIGNCLR);
 	au_writel(0xffffffff, IC1_WAKECLR);
 	au_writel(0xffffffff, IC1_SRCSET);
 	au_writel(0xffffffff, IC1_FALLINGCLR);