r6040: handle RX fifo full and no descriptor interrupts

This patch allows the MAC to handle the RX FIFO full
and no descriptor available interrupts. While we are at it
replace the TX interrupt with its corresponding definition.
Signed-off-by: Florian Fainelli <florian.fainelli@telecomint.eu>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/net/r6040.c

@@ -163,9 +163,9 @@ MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("RDC R6040 NAPI PCI FastEthernet driver");
 
 /* RX and TX interrupts that we handle */
-#define RX_INT			(RX_FINISH)
-#define TX_INT			(TX_FINISH)
-#define INT_MASK		(RX_INT | TX_INT)
+#define RX_INTS			(RX_FIFO_FULL | RX_NO_DESC | RX_FINISH)
+#define TX_INTS			(TX_FINISH)
+#define INT_MASK		(RX_INTS | TX_INTS)
 
 struct r6040_descriptor {
 	u16	status, len;		/* 0-3 */
@@ -671,7 +671,7 @@ static int r6040_poll(struct napi_struct *napi, int budget)
 	if (work_done < budget) {
 		netif_rx_complete(dev, napi);
 		/* Enable RX interrupt */
-		iowrite16(ioread16(ioaddr + MIER) | RX_INT, ioaddr + MIER);
+		iowrite16(ioread16(ioaddr + MIER) | RX_INTS, ioaddr + MIER);
 	}
 	return work_done;
 }
@@ -693,14 +693,22 @@ static irqreturn_t r6040_interrupt(int irq, void *dev_id)
 		return IRQ_NONE;
 
 	/* RX interrupt request */
-	if (status & 0x01) {
+	if (status & RX_INTS) {
+		if (status & RX_NO_DESC) {
+			/* RX descriptor unavailable */
+			dev->stats.rx_dropped++;
+			dev->stats.rx_missed_errors++;
+		}
+		if (status & RX_FIFO_FULL)
+			dev->stats.rx_fifo_errors++;
+
 		/* Mask off RX interrupt */
-		iowrite16(ioread16(ioaddr + MIER) & ~RX_INT, ioaddr + MIER);
+		iowrite16(ioread16(ioaddr + MIER) & ~RX_INTS, ioaddr + MIER);
 		netif_rx_schedule(dev, &lp->napi);
 	}
 
 	/* TX interrupt request */
-	if (status & 0x10)
+	if (status & TX_INTS)
 		r6040_tx(dev);
 
 	return IRQ_HANDLED;