net: mt7628-eth: free rx descriptor on receiving failure

When received a packet with an invalid length recorded in rx descriptor,
we should free this rx descriptor to allow us to continue to receive
following packets.
Without doing so, u-boot will stuck in a dead loop trying to process this
invalid rx descriptor.

This patch adds a call to mt7628_eth_free_pkt() after received an invalid
packet length.

Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>

diff --git a/drivers/net/mt7628-eth.c b/drivers/net/mt7628-eth.c
index abfdc75ad8d4da1c42e7a2a316b637960d3d7b57..d77da26d50a3da82b26ce1c61be593818e7e3b91 100644 (file)
--- a/drivers/net/mt7628-eth.c
+++ b/drivers/net/mt7628-eth.c
@@ -142,6 +142,8 @@ struct mt7628_eth_dev {
        struct phy_device *phy;
 };
 
+static int mt7628_eth_free_pkt(struct udevice *dev, uchar *packet, int length);
+
 static int mdio_wait_read(struct mt7628_eth_dev *priv, u32 mask, bool mask_set)
 {
        void __iomem *base = priv->eth_sw_base;
@@ -403,6 +405,7 @@ static int mt7628_eth_recv(struct udevice *dev, int flags, uchar **packetp)
        length = FIELD_GET(RX_DMA_PLEN0, priv->rx_ring[idx].rxd2);
        if (length == 0 || length > MTK_QDMA_PAGE_SIZE) {
                printf("%s: invalid length (%d bytes)\n", __func__, length);
+               mt7628_eth_free_pkt(dev, NULL, 0);
                return -EIO;
        }