rt2x00: Convert rt2x00 to use threaded interrupts

Use threaded interrupts for all rt2x00 PCI devices.

This has several generic advantages:
- Reduce the time we spend in hard irq context
- Use non-atmic mac80211 functions for rx/tx

Furthermore implementing broad- and multicast buffering will be
much easier in process context while maintaining low latency and
updating the beacon just before transmission (pre tbtt interrupt)
can also be done in process context.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2800pci.c b/drivers/net/wireless/rt2x00/rt2800pci.c
index a9eca99d..f21b77c 100644
--- a/drivers/net/wireless/rt2x00/rt2800pci.c
+++ b/drivers/net/wireless/rt2x00/rt2800pci.c
@@ -422,7 +422,8 @@
 static void rt2800pci_toggle_irq(struct rt2x00_dev *rt2x00dev,
 				 enum dev_state state)
 {
-	int mask = (state == STATE_RADIO_IRQ_ON);
+	int mask = (state == STATE_RADIO_IRQ_ON) ||
+		   (state == STATE_RADIO_IRQ_ON_ISR);
 	u32 reg;
 
 	/*
@@ -631,7 +632,9 @@
 		rt2800pci_toggle_rx(rt2x00dev, state);
 		break;
 	case STATE_RADIO_IRQ_ON:
+	case STATE_RADIO_IRQ_ON_ISR:
 	case STATE_RADIO_IRQ_OFF:
+	case STATE_RADIO_IRQ_OFF_ISR:
 		rt2800pci_toggle_irq(rt2x00dev, state);
 		break;
 	case STATE_DEEP_SLEEP:
@@ -929,20 +932,10 @@
 	rt2800_config(rt2x00dev, &libconf, IEEE80211_CONF_CHANGE_PS);
 }
 
-static irqreturn_t rt2800pci_interrupt(int irq, void *dev_instance)
+static irqreturn_t rt2800pci_interrupt_thread(int irq, void *dev_instance)
 {
 	struct rt2x00_dev *rt2x00dev = dev_instance;
-	u32 reg;
-
-	/* Read status and ACK all interrupts */
-	rt2800_register_read(rt2x00dev, INT_SOURCE_CSR, &reg);
-	rt2800_register_write(rt2x00dev, INT_SOURCE_CSR, reg);
-
-	if (!reg)
-		return IRQ_NONE;
-
-	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
-		return IRQ_HANDLED;
+	u32 reg = rt2x00dev->irqvalue[0];
 
 	/*
 	 * 1 - Rx ring done interrupt.
@@ -962,9 +955,39 @@
 	if (rt2x00_get_field32(reg, INT_SOURCE_CSR_AUTO_WAKEUP))
 		rt2800pci_wakeup(rt2x00dev);
 
+	/* Enable interrupts again. */
+	rt2x00dev->ops->lib->set_device_state(rt2x00dev,
+					      STATE_RADIO_IRQ_ON_ISR);
+
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t rt2800pci_interrupt(int irq, void *dev_instance)
+{
+	struct rt2x00_dev *rt2x00dev = dev_instance;
+	u32 reg;
+
+	/* Read status and ACK all interrupts */
+	rt2800_register_read(rt2x00dev, INT_SOURCE_CSR, &reg);
+	rt2800_register_write(rt2x00dev, INT_SOURCE_CSR, reg);
+
+	if (!reg)
+		return IRQ_NONE;
+
+	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
+		return IRQ_HANDLED;
+
+	/* Store irqvalue for use in the interrupt thread. */
+	rt2x00dev->irqvalue[0] = reg;
+
+	/* Disable interrupts, will be enabled again in the interrupt thread. */
+	rt2x00dev->ops->lib->set_device_state(rt2x00dev,
+					      STATE_RADIO_IRQ_OFF_ISR);
+
+
+	return IRQ_WAKE_THREAD;
+}
+
 /*
  * Device probe functions.
  */
@@ -1049,6 +1072,7 @@
 
 static const struct rt2x00lib_ops rt2800pci_rt2x00_ops = {
 	.irq_handler		= rt2800pci_interrupt,
+	.irq_handler_thread	= rt2800pci_interrupt_thread,
 	.probe_hw		= rt2800pci_probe_hw,
 	.get_firmware_name	= rt2800pci_get_firmware_name,
 	.check_firmware		= rt2800pci_check_firmware,