3 files changed, 42 insertions, 40 deletions

diff --git a/drivers/net/wireless/b43/b43.h b/drivers/net/wireless/b43/b43.h
index 239e71c3d1b1..532365f5ecef 100644
--- a/drivers/net/wireless/b43/b43.h
+++ b/drivers/net/wireless/b43/b43.h
@@ -649,7 +649,6 @@ struct b43_pio {
 
 /* Context information for a noise calculation (Link Quality). */
 struct b43_noise_calculation {
-	u8 channel_at_start;
 	bool calculation_running;
 	u8 nr_samples;
 	s8 samples[8][4];
diff --git a/drivers/net/wireless/b43/dma.c b/drivers/net/wireless/b43/dma.c
index b4eadd908bea..8a09a1db08db 100644
--- a/drivers/net/wireless/b43/dma.c
+++ b/drivers/net/wireless/b43/dma.c
@@ -795,24 +795,49 @@ struct b43_dmaring *b43_setup_dmaring(struct b43_wldev *dev,
 {
 	struct b43_dmaring *ring;
 	int err;
-	int nr_slots;
 	dma_addr_t dma_test;
 
 	ring = kzalloc(sizeof(*ring), GFP_KERNEL);
 	if (!ring)
 		goto out;
-	ring->type = type;
 
-	nr_slots = B43_RXRING_SLOTS;
+	ring->nr_slots = B43_RXRING_SLOTS;
 	if (for_tx)
-		nr_slots = B43_TXRING_SLOTS;
+		ring->nr_slots = B43_TXRING_SLOTS;
 
-	ring->meta = kcalloc(nr_slots, sizeof(struct b43_dmadesc_meta),
+	ring->meta = kcalloc(ring->nr_slots, sizeof(struct b43_dmadesc_meta),
 			     GFP_KERNEL);
 	if (!ring->meta)
 		goto err_kfree_ring;
+
+	ring->type = type;
+	ring->dev = dev;
+	ring->mmio_base = b43_dmacontroller_base(type, controller_index);
+	ring->index = controller_index;
+	if (type == B43_DMA_64BIT)
+		ring->ops = &dma64_ops;
+	else
+		ring->ops = &dma32_ops;
 	if (for_tx) {
-		ring->txhdr_cache = kcalloc(nr_slots,
+		ring->tx = 1;
+		ring->current_slot = -1;
+	} else {
+		if (ring->index == 0) {
+			ring->rx_buffersize = B43_DMA0_RX_BUFFERSIZE;
+			ring->frameoffset = B43_DMA0_RX_FRAMEOFFSET;
+		} else if (ring->index == 3) {
+			ring->rx_buffersize = B43_DMA3_RX_BUFFERSIZE;
+			ring->frameoffset = B43_DMA3_RX_FRAMEOFFSET;
+		} else
+			B43_WARN_ON(1);
+	}
+	spin_lock_init(&ring->lock);
+#ifdef CONFIG_B43_DEBUG
+	ring->last_injected_overflow = jiffies;
+#endif
+
+	if (for_tx) {
+		ring->txhdr_cache = kcalloc(ring->nr_slots,
 					    b43_txhdr_size(dev),
 					    GFP_KERNEL);
 		if (!ring->txhdr_cache)
@@ -828,7 +853,7 @@ struct b43_dmaring *b43_setup_dmaring(struct b43_wldev *dev,
 					  b43_txhdr_size(dev), 1)) {
 			/* ugh realloc */
 			kfree(ring->txhdr_cache);
-			ring->txhdr_cache = kcalloc(nr_slots,
+			ring->txhdr_cache = kcalloc(ring->nr_slots,
 						    b43_txhdr_size(dev),
 						    GFP_KERNEL | GFP_DMA);
 			if (!ring->txhdr_cache)
@@ -853,32 +878,6 @@ struct b43_dmaring *b43_setup_dmaring(struct b43_wldev *dev,
 				 DMA_TO_DEVICE);
 	}
 
-	ring->dev = dev;
-	ring->nr_slots = nr_slots;
-	ring->mmio_base = b43_dmacontroller_base(type, controller_index);
-	ring->index = controller_index;
-	if (type == B43_DMA_64BIT)
-		ring->ops = &dma64_ops;
-	else
-		ring->ops = &dma32_ops;
-	if (for_tx) {
-		ring->tx = 1;
-		ring->current_slot = -1;
-	} else {
-		if (ring->index == 0) {
-			ring->rx_buffersize = B43_DMA0_RX_BUFFERSIZE;
-			ring->frameoffset = B43_DMA0_RX_FRAMEOFFSET;
-		} else if (ring->index == 3) {
-			ring->rx_buffersize = B43_DMA3_RX_BUFFERSIZE;
-			ring->frameoffset = B43_DMA3_RX_FRAMEOFFSET;
-		} else
-			B43_WARN_ON(1);
-	}
-	spin_lock_init(&ring->lock);
-#ifdef CONFIG_B43_DEBUG
-	ring->last_injected_overflow = jiffies;
-#endif
-
 	err = alloc_ringmemory(ring);
 	if (err)
 		goto err_kfree_txhdr_cache;
diff --git a/drivers/net/wireless/b43/main.c b/drivers/net/wireless/b43/main.c
index 1e31e0bca744..7bca8e981512 100644
--- a/drivers/net/wireless/b43/main.c
+++ b/drivers/net/wireless/b43/main.c
@@ -1145,7 +1145,6 @@ static void b43_generate_noise_sample(struct b43_wldev *dev)
 	b43_jssi_write(dev, 0x7F7F7F7F);
 	b43_write32(dev, B43_MMIO_MACCMD,
 		    b43_read32(dev, B43_MMIO_MACCMD) | B43_MACCMD_BGNOISE);
-	B43_WARN_ON(dev->noisecalc.channel_at_start != dev->phy.channel);
 }
 
 static void b43_calculate_link_quality(struct b43_wldev *dev)
@@ -1154,7 +1153,6 @@ static void b43_calculate_link_quality(struct b43_wldev *dev)
 
 	if (dev->noisecalc.calculation_running)
 		return;
-	dev->noisecalc.channel_at_start = dev->phy.channel;
 	dev->noisecalc.calculation_running = 1;
 	dev->noisecalc.nr_samples = 0;
 
@@ -1171,9 +1169,16 @@ static void handle_irq_noise(struct b43_wldev *dev)
 
 	/* Bottom half of Link Quality calculation. */
 
+	/* Possible race condition: It might be possible that the user
+	 * changed to a different channel in the meantime since we
+	 * started the calculation. We ignore that fact, since it's
+	 * not really that much of a problem. The background noise is
+	 * an estimation only anyway. Slightly wrong results will get damped
+	 * by the averaging of the 8 sample rounds. Additionally the
+	 * value is shortlived. So it will be replaced by the next noise
+	 * calculation round soon. */
+
 	B43_WARN_ON(!dev->noisecalc.calculation_running);
-	if (dev->noisecalc.channel_at_start != phy->channel)
-		goto drop_calculation;
 	*((__le32 *)noise) = cpu_to_le32(b43_jssi_read(dev));
 	if (noise[0] == 0x7F || noise[1] == 0x7F ||
 	    noise[2] == 0x7F || noise[3] == 0x7F)
@@ -1214,11 +1219,10 @@ static void handle_irq_noise(struct b43_wldev *dev)
 			average -= 48;
 
 		dev->stats.link_noise = average;
-	      drop_calculation:
 		dev->noisecalc.calculation_running = 0;
 		return;
 	}
-      generate_new:
+generate_new:
 	b43_generate_noise_sample(dev);
 }