cns3xxx: prevent the ethernet driver from accessing uninitialized dma descriptor...

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@35950 3c298f89-4303-0410-b956-a3cf2f4a3e73

diff --git a/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c b/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c
index 7a5c44c..c9040b1 100644 (file)
--- a/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c
+++ b/target/linux/cns3xxx/files/drivers/net/ethernet/cavium/cns3xxx_eth.c
@@ -619,8 +619,9 @@ static int eth_poll(struct napi_struct *napi, int budget)
        unsigned int length;
        unsigned int i = rx_ring->cur_index;
        struct rx_desc *desc = &(rx_ring)->desc[i];
+       unsigned int alloc_count = rx_ring->alloc_count;
 
-       while (desc->cown) {
+       while (desc->cown && alloc_count + received < RX_DESCS - 1) {
                struct sk_buff *skb;
                int reserve = SKB_HEAD_ALIGN;