net: stmmac: reset Tx desc base address before restarting Tx

Refer to the databook of DesignWare Cores Ethernet MAC Universal:

6.2.1.5 Register 4 (Transmit Descriptor List Address Register

If this register is not changed when the ST bit is set to 0, then
the DMA takes the descriptor address where it was stopped earlier.

The stmmac_tx_err() does zero indices to Tx descriptors, but does
not reset HW current Tx descriptor address. To fix inconsistency,
the base address of the Tx descriptors should be rewritten before
restarting Tx.

Signed-off-by: Jongsung Kim <neidhard.kim@lge.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 644cb5d1fd4f4a4ff9652c4debfe50b6bd2c3694..bbc65bd332a8ba9e0cf5f8a4ac353434dfb8e0cc 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -2009,6 +2009,8 @@ static void stmmac_tx_err(struct stmmac_priv *priv, u32 chan)
        tx_q->cur_tx = 0;
        tx_q->mss = 0;
        netdev_tx_reset_queue(netdev_get_tx_queue(priv->dev, chan));
+       stmmac_init_tx_chan(priv, priv->ioaddr, priv->plat->dma_cfg,
+                           tx_q->dma_tx_phy, chan);
        stmmac_start_tx_dma(priv, chan);
 
        priv->dev->stats.tx_errors++;