3 files changed, 42 insertions, 40 deletions

diff --git a/drivers/net/wireless/b43/b43.h b/drivers/net/wireless/b43/b43.h
index dfa4bdd5597c..d3db298c05fc 100644
--- a/drivers/net/wireless/b43/b43.h
+++ b/drivers/net/wireless/b43/b43.h
@@ -630,7 +630,6 @@ 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 6dcbb3c87e72..e23f2f172bd7 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 6c3d9ea0a9f8..fa4b0d8b74a2 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);
 }