1 files changed, 14 insertions, 47 deletions

diff --git a/drivers/net/ethernet/atheros/alx/main.c b/drivers/net/ethernet/atheros/alx/main.c
index c98acdc0d14f..e708e360a9e3 100644
--- a/drivers/net/ethernet/atheros/alx/main.c
+++ b/drivers/net/ethernet/atheros/alx/main.c
@@ -70,35 +70,6 @@ static void alx_free_txbuf(struct alx_priv *alx, int entry)
         }
 }
 
-static struct sk_buff *alx_alloc_skb(struct alx_priv *alx, gfp_t gfp)
-{
-        struct sk_buff *skb;
-        struct page *page;
-
-        if (alx->rx_frag_size > PAGE_SIZE)
-                return __netdev_alloc_skb(alx->dev, alx->rxbuf_size, gfp);
-
-        page = alx->rx_page;
-        if (!page) {
-                alx->rx_page = page = alloc_page(gfp);
-                if (unlikely(!page))
-                        return NULL;
-                alx->rx_page_offset = 0;
-        }
-
-        skb = build_skb(page_address(page) + alx->rx_page_offset,
-                        alx->rx_frag_size);
-        if (likely(skb)) {
-                alx->rx_page_offset += alx->rx_frag_size;
-                if (alx->rx_page_offset >= PAGE_SIZE)
-                        alx->rx_page = NULL;
-                else
-                        get_page(page);
-        }
-        return skb;
-}
-
-
 static int alx_refill_rx_ring(struct alx_priv *alx, gfp_t gfp)
 {
         struct alx_rx_queue *rxq = &alx->rxq;
@@ -115,9 +86,22 @@ static int alx_refill_rx_ring(struct alx_priv *alx, gfp_t gfp)
         while (!cur_buf->skb && next != rxq->read_idx) {
                 struct alx_rfd *rfd = &rxq->rfd[cur];
 
-                skb = alx_alloc_skb(alx, gfp);
+                /*
+                 * When DMA RX address is set to something like
+                 * 0x....fc0, it will be very likely to cause DMA
+                 * RFD overflow issue.
+                 *
+                 * To work around it, we apply rx skb with 64 bytes
+                 * longer space, and offset the address whenever
+                 * 0x....fc0 is detected.
+                 */
+                skb = __netdev_alloc_skb(alx->dev, alx->rxbuf_size + 64, gfp);
                 if (!skb)
                         break;
+
+                if (((unsigned long)skb->data & 0xfff) == 0xfc0)
+                        skb_reserve(skb, 64);
+
                 dma = dma_map_single(&alx->hw.pdev->dev,
                                      skb->data, alx->rxbuf_size,
                                      DMA_FROM_DEVICE);
@@ -153,7 +137,6 @@ static int alx_refill_rx_ring(struct alx_priv *alx, gfp_t gfp)
                 alx_write_mem16(&alx->hw, ALX_RFD_PIDX, cur);
         }
 
-
         return count;
 }
 
@@ -622,11 +605,6 @@ static void alx_free_rings(struct alx_priv *alx)
         kfree(alx->txq.bufs);
         kfree(alx->rxq.bufs);
 
-        if (alx->rx_page) {
-                put_page(alx->rx_page);
-                alx->rx_page = NULL;
-        }
-
         dma_free_coherent(&alx->hw.pdev->dev,
                           alx->descmem.size,
                           alx->descmem.virt,
@@ -681,7 +659,6 @@ static int alx_request_irq(struct alx_priv *alx)
                                   alx->dev->name, alx);
                 if (!err)
                         goto out;
-
                 /* fall back to legacy interrupt */
                 pci_disable_msi(alx->hw.pdev);
         }
@@ -725,7 +702,6 @@ static int alx_init_sw(struct alx_priv *alx)
         struct pci_dev *pdev = alx->hw.pdev;
         struct alx_hw *hw = &alx->hw;
         int err;
-        unsigned int head_size;
 
         err = alx_identify_hw(alx);
         if (err) {
@@ -741,12 +717,7 @@ static int alx_init_sw(struct alx_priv *alx)
 
         hw->smb_timer = 400;
         hw->mtu = alx->dev->mtu;
-
         alx->rxbuf_size = ALX_MAX_FRAME_LEN(hw->mtu);
-        head_size = SKB_DATA_ALIGN(alx->rxbuf_size + NET_SKB_PAD) +
-                    SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
-        alx->rx_frag_size = roundup_pow_of_two(head_size);
-
         alx->tx_ringsz = 256;
         alx->rx_ringsz = 512;
         hw->imt = 200;
@@ -848,7 +819,6 @@ static int alx_change_mtu(struct net_device *netdev, int mtu)
 {
         struct alx_priv *alx = netdev_priv(netdev);
         int max_frame = ALX_MAX_FRAME_LEN(mtu);
-        unsigned int head_size;
 
         if ((max_frame < ALX_MIN_FRAME_SIZE) ||
             (max_frame > ALX_MAX_FRAME_SIZE))
@@ -860,9 +830,6 @@ static int alx_change_mtu(struct net_device *netdev, int mtu)
         netdev->mtu = mtu;
         alx->hw.mtu = mtu;
         alx->rxbuf_size = max(max_frame, ALX_DEF_RXBUF_SIZE);
-        head_size = SKB_DATA_ALIGN(alx->rxbuf_size + NET_SKB_PAD) +
-                    SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
-        alx->rx_frag_size = roundup_pow_of_two(head_size);
         netdev_update_features(netdev);
         if (netif_running(netdev))
                 alx_reinit(alx);