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 | 63 |
1 files changed, 36 insertions, 27 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 index d6feed05b2..2ca9d10f63 100644 --- 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 @@ -1,19 +1,40 @@ From: Felix Fietkau <nbd@openwrt.org> Date: Sun, 12 Apr 2015 22:23:07 +0200 -Subject: [PATCH] bgmac: simplify rx DMA error handling +Subject: [PATCH] bgmac: simplify/optimize rx DMA error handling -Unmap the DMA buffer before checking it. If an error occurs, free the -buffer and allocate a new one. If allocation or mapping fails, retry as -long as there is NAPI poll budget left (count every attempt instead of -every frame). +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 -@@ -404,51 +404,33 @@ static int bgmac_dma_rx_read(struct bgma +@@ -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 */ @@ -23,19 +44,19 @@ Signed-off-by: Felix Fietkau <nbd@openwrt.org> - /* Get info from the header */ - len = le16_to_cpu(rx->len); - flags = le16_to_cpu(rx->flags); -+ if (++handled >= weight - 1) /* Should never be greater */ -+ break; - +- do { - dma_addr_t old_dma_addr = slot->dma_addr; - int err; -+ if (!slot->dma_addr) ++ /* 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, slot->dma_addr, ++ dma_unmap_single(dma_dev, dma_addr, + BGMAC_RX_BUF_SIZE, DMA_FROM_DEVICE); -+ slot->dma_addr = 0; + + /* Get info from the header */ + len = le16_to_cpu(rx->len); @@ -78,28 +99,16 @@ Signed-off-by: Felix Fietkau <nbd@openwrt.org> skb = build_skb(buf, BGMAC_RX_ALLOC_SIZE); skb_put(skb, BGMAC_RX_FRAME_OFFSET + BGMAC_RX_BUF_OFFSET + len); -@@ -458,14 +440,16 @@ static int bgmac_dma_rx_read(struct bgma - skb_checksum_none_assert(skb); - skb->protocol = eth_type_trans(skb, bgmac->net_dev); - napi_gro_receive(&bgmac->napi, skb); -- handled++; +@@ -465,6 +460,8 @@ static int bgmac_dma_rx_read(struct bgma + handled++; } while (0); -+ /* Prepare new skb as replacement */ -+ if (bgmac_dma_rx_skb_for_slot(bgmac, slot)) -+ continue; -+ + bgmac_dma_rx_setup_desc(bgmac, ring, ring->start); + if (++ring->start >= BGMAC_RX_RING_SLOTS) ring->start = 0; -- -- if (handled >= weight) /* Should never be greater */ -- break; - } - return handled; -@@ -528,14 +512,14 @@ static void bgmac_dma_rx_ring_free(struc +@@ -532,14 +529,14 @@ static void bgmac_dma_rx_ring_free(struc for (i = 0; i < ring->num_slots; i++) { slot = &ring->slots[i]; |