From bcdb12b70c5266a78430a248e57c8c122839b951 Mon Sep 17 00:00:00 2001 From: Fuyun Liang Date: Tue, 16 Oct 2018 19:58:52 +0800 Subject: [PATCH] net: hns3: fix for multiple unmapping DMA problem When sending a big fragment using multiple buffer descriptor, hns3 does one maping, but do multiple unmapping when tx is done, which may cause unmapping problem. To fix it, this patch makes sure the value of desc_cb.length of the non-first bd is zero. If desc_cb.length is zero, we do not unmap the buffer. Fixes: 76ad4f0ee747 ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC") Signed-off-by: Fuyun Liang Signed-off-by: Peng Li Signed-off-by: Yunsheng Lin Signed-off-by: David S. Miller --- drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c index 74e592dd5e20..76ce2f21178b 100644 --- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c +++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c @@ -1051,6 +1051,8 @@ static int hns3_fill_desc(struct hns3_enet_ring *ring, void *priv, return -ENOMEM; } + desc_cb->length = size; + frag_buf_num = (size + HNS3_MAX_BD_SIZE - 1) / HNS3_MAX_BD_SIZE; sizeoflast = size % HNS3_MAX_BD_SIZE; sizeoflast = sizeoflast ? sizeoflast : HNS3_MAX_BD_SIZE; @@ -1059,15 +1061,14 @@ static int hns3_fill_desc(struct hns3_enet_ring *ring, void *priv, for (k = 0; k < frag_buf_num; k++) { /* The txbd's baseinfo of DESC_TYPE_PAGE & DESC_TYPE_SKB */ desc_cb->priv = priv; - desc_cb->length = (k == frag_buf_num - 1) ? - sizeoflast : HNS3_MAX_BD_SIZE; desc_cb->dma = dma + HNS3_MAX_BD_SIZE * k; desc_cb->type = (type == DESC_TYPE_SKB && !k) ? DESC_TYPE_SKB : DESC_TYPE_PAGE; /* now, fill the descriptor */ desc->addr = cpu_to_le64(dma + HNS3_MAX_BD_SIZE * k); - desc->tx.send_size = cpu_to_le16((u16)desc_cb->length); + desc->tx.send_size = cpu_to_le16((k == frag_buf_num - 1) ? + (u16)sizeoflast : (u16)HNS3_MAX_BD_SIZE); hns3_set_txbd_baseinfo(&bdtp_fe_sc_vld_ra_ri, frag_end && (k == frag_buf_num - 1) ? 1 : 0); @@ -1150,12 +1151,14 @@ static void hns3_clear_desc(struct hns3_enet_ring *ring, int next_to_use_orig) ring->desc_cb[ring->next_to_use].dma, ring->desc_cb[ring->next_to_use].length, DMA_TO_DEVICE); - else + else if (ring->desc_cb[ring->next_to_use].length) dma_unmap_page(dev, ring->desc_cb[ring->next_to_use].dma, ring->desc_cb[ring->next_to_use].length, DMA_TO_DEVICE); + ring->desc_cb[ring->next_to_use].length = 0; + /* rollback one */ ring_ptr_move_bw(ring, next_to_use); } @@ -1874,7 +1877,7 @@ static void hns3_unmap_buffer(struct hns3_enet_ring *ring, if (cb->type == DESC_TYPE_SKB) dma_unmap_single(ring_to_dev(ring), cb->dma, cb->length, ring_to_dma_dir(ring)); - else + else if (cb->length) dma_unmap_page(ring_to_dev(ring), cb->dma, cb->length, ring_to_dma_dir(ring)); } -- GitLab