diff options
Diffstat (limited to 'target/linux/generic/patches-3.18/077-07-bgmac-simplify-rx-DMA-error-handling.patch')
| -rw-r--r-- | target/linux/generic/patches-3.18/077-07-bgmac-simplify-rx-DMA-error-handling.patch | 130 |
1 files changed, 130 insertions, 0 deletions
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 index 0000000..2ca9d10 --- /dev/null +++ b/target/linux/generic/patches-3.18/077-07-bgmac-simplify-rx-DMA-error-handling.patch @@ -0,0 +1,130 @@ +From: Felix Fietkau <nbd@openwrt.org> +Date: Sun, 12 Apr 2015 22:23:07 +0200 +Subject: [PATCH] bgmac: simplify/optimize rx DMA error handling + +Allocate a new buffer before processing the completed one. If allocation +fails, reuse the old buffer. + +Signed-off-by: Felix Fietkau <nbd@openwrt.org> +--- + +--- a/drivers/net/ethernet/broadcom/bgmac.c ++++ b/drivers/net/ethernet/broadcom/bgmac.c +@@ -386,6 +386,19 @@ static void bgmac_dma_rx_setup_desc(stru + dma_desc->ctl1 = cpu_to_le32(ctl1); + } + ++static void bgmac_dma_rx_poison_buf(struct device *dma_dev, ++ struct bgmac_slot_info *slot) ++{ ++ struct bgmac_rx_header *rx = slot->buf + BGMAC_RX_BUF_OFFSET; ++ ++ dma_sync_single_for_cpu(dma_dev, slot->dma_addr, BGMAC_RX_BUF_SIZE, ++ DMA_FROM_DEVICE); ++ 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); ++} ++ + static int bgmac_dma_rx_read(struct bgmac *bgmac, struct bgmac_dma_ring *ring, + int weight) + { +@@ -406,53 +419,35 @@ static int bgmac_dma_rx_read(struct bgma + struct bgmac_rx_header *rx = slot->buf + BGMAC_RX_BUF_OFFSET; + struct sk_buff *skb; + void *buf = slot->buf; ++ dma_addr_t dma_addr = slot->dma_addr; + 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); +- +- /* 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; ++ /* Prepare new skb as replacement */ ++ if (bgmac_dma_rx_skb_for_slot(bgmac, slot)) { ++ bgmac_dma_rx_poison_buf(dma_dev, slot); ++ break; ++ } ++ ++ /* Unmap buffer to make it accessible to the CPU */ ++ dma_unmap_single(dma_dev, 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); + + /* 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); ++ put_page(virt_to_head_page(buf)); + break; + } + + /* Omit CRC. */ + len -= ETH_FCS_LEN; + +- /* Prepare new skb as replacement */ +- err = bgmac_dma_rx_skb_for_slot(bgmac, slot); +- if (err) { +- /* 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 + + BGMAC_RX_BUF_OFFSET + len); +@@ -465,6 +460,8 @@ 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; + +@@ -532,14 +529,14 @@ static void bgmac_dma_rx_ring_free(struc + + for (i = 0; i < ring->num_slots; i++) { + slot = &ring->slots[i]; +- if (!slot->buf) ++ if (!slot->dma_addr) + continue; + +- if (slot->dma_addr) +- dma_unmap_single(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); + put_page(virt_to_head_page(slot->buf)); ++ slot->dma_addr = 0; + } + } + |