kernel: bgmac: add more DMA related fixes

[openwrt/svn-archive/archive.git] / target / linux / generic / patches-3.18 / 077-07-bgmac-simplify-rx-DMA-error-handling.patch

diff --git a/target/linux/generic/patches-3.18/077-07-bgmac-simplify-rx-DMA-error-handling.patch b/target/linux/generic/patches-3.18/077-07-bgmac-simplify-rx-DMA-error-handling.patch
new file mode 100644 (file)
index 0000000..f26e42c
--- /dev/null
+++ b/target/linux/generic/patches-3.18/077-07-bgmac-simplify-rx-DMA-error-handling.patch
@@ -0,0 +1,68 @@
+From: Felix Fietkau <nbd@openwrt.org>
+Date: Sun, 12 Apr 2015 22:23:07 +0200
+Subject: [PATCH] bgmac: simplify rx DMA error handling
+
+Unmap the DMA buffer before checking it. If it is poisoned, map it again
+and pass it back to the hardware.
+
+Signed-off-by: Felix Fietkau <nbd@openwrt.org>
+---
+
+--- a/drivers/net/ethernet/broadcom/bgmac.c
++++ b/drivers/net/ethernet/broadcom/bgmac.c
+@@ -405,25 +405,20 @@ static int bgmac_dma_rx_read(struct bgma
+               u16 len, flags;
+ 
+               /* Unmap buffer to make it accessible to the CPU */
+-              dma_sync_single_for_cpu(dma_dev, slot->dma_addr,
+-                                      BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE);
++              dma_unmap_single(dma_dev, slot->dma_addr,
++                               BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE);
+ 
+               /* Get info from the header */
+               len = le16_to_cpu(rx->len);
+               flags = le16_to_cpu(rx->flags);
+ 
+               do {
+-                      dma_addr_t old_dma_addr = slot->dma_addr;
+                       int err;
+ 
+                       /* Check for poison and drop or pass the packet */
+                       if (len == 0xdead && flags == 0xbeef) {
+                               bgmac_err(bgmac, "Found poisoned packet at slot %d, DMA issue!\n",
+                                         ring->start);
+-                              dma_sync_single_for_device(dma_dev,
+-                                                         slot->dma_addr,
+-                                                         BGMAC_RX_BUF_SIZE,
+-                                                         DMA_FROM_DEVICE);
+                               break;
+                       }
+ 
+@@ -436,18 +431,8 @@ static int bgmac_dma_rx_read(struct bgma
+                               /* Poison the old skb */
+                               rx->len = cpu_to_le16(0xdead);
+                               rx->flags = cpu_to_le16(0xbeef);
+-
+-                              dma_sync_single_for_device(dma_dev,
+-                                                         slot->dma_addr,
+-                                                         BGMAC_RX_BUF_SIZE,
+-                                                         DMA_FROM_DEVICE);
+                               break;
+                       }
+-                      bgmac_dma_rx_setup_desc(bgmac, ring, ring->start);
+-
+-                      /* Unmap old skb, we'll pass it to the netfif */
+-                      dma_unmap_single(dma_dev, old_dma_addr,
+-                                       BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE);
+ 
+                       skb = build_skb(buf, BGMAC_RX_ALLOC_SIZE);
+                       skb_put(skb, BGMAC_RX_FRAME_OFFSET +
+@@ -461,6 +446,8 @@ static int bgmac_dma_rx_read(struct bgma
+                       handled++;
+               } while (0);
+ 
++              bgmac_dma_rx_setup_desc(bgmac, ring, ring->start);
++
+               if (++ring->start >= BGMAC_RX_RING_SLOTS)
+                       ring->start = 0;
+