b43: Add optional verbose runtime statistics

This adds support for verbose runtime statistics.
It defaults to off and must be enabled in debugfs, if desired.
The first measurement may be incorrect, because statistics are not cleared
after they got enabled through debugfs.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index 7d22dad..6468bbe 100644
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -1830,6 +1830,16 @@
 
 	/* Re-enable interrupts on the device by restoring the current interrupt mask. */
 	b43_write32(dev, B43_MMIO_GEN_IRQ_MASK, dev->irq_mask);
+
+#if B43_DEBUG
+	if (b43_debug(dev, B43_DBG_VERBOSESTATS)) {
+		dev->irq_count++;
+		for (i = 0; i < ARRAY_SIZE(dev->irq_bit_count); i++) {
+			if (reason & (1 << i))
+				dev->irq_bit_count[i]++;
+		}
+	}
+#endif
 }
 
 /* Interrupt thread handler. Handles device interrupts in thread context. */
@@ -2893,6 +2903,27 @@
 
 	atomic_set(&phy->txerr_cnt, B43_PHY_TX_BADNESS_LIMIT);
 	wmb();
+
+#if B43_DEBUG
+	if (b43_debug(dev, B43_DBG_VERBOSESTATS)) {
+		unsigned int i;
+
+		b43dbg(dev->wl, "Stats: %7u IRQs/sec, %7u TX/sec, %7u RX/sec\n",
+		       dev->irq_count / 15,
+		       dev->tx_count / 15,
+		       dev->rx_count / 15);
+		dev->irq_count = 0;
+		dev->tx_count = 0;
+		dev->rx_count = 0;
+		for (i = 0; i < ARRAY_SIZE(dev->irq_bit_count); i++) {
+			if (dev->irq_bit_count[i]) {
+				b43dbg(dev->wl, "Stats: %7u IRQ-%02u/sec (0x%08X)\n",
+				       dev->irq_bit_count[i] / 15, i, (1 << i));
+				dev->irq_bit_count[i] = 0;
+			}
+		}
+	}
+#endif
 }
 
 static void do_periodic_work(struct b43_wldev *dev)
@@ -3092,6 +3123,9 @@
 			dev_kfree_skb(skb); /* Drop it */
 	}
 
+#if B43_DEBUG
+	dev->tx_count++;
+#endif
 	mutex_unlock(&wl->mutex);
 }