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authorEsben Haabendal <esben@geanix.com>2019-04-30 10:17:59 +0300
committerDavid S. Miller <davem@davemloft.net>2019-05-01 21:33:31 +0300
commit73f7375d3ed6ad372f1e9404007a0c866063d773 (patch)
treeb8b355013ec19637c6f26d2686e6975b877c5942
parent7e97a194aca03c6ff86f84e46e196f5c9ed5c32c (diff)
downloadlinux-73f7375d3ed6ad372f1e9404007a0c866063d773.tar.xz
net: ll_temac: Enable DMA when ready, not before
As soon as TAILDESCR_PTR is written, DMA transfers might start. Let's ensure we are ready to receive DMA IRQ's before doing that. Signed-off-by: Esben Haabendal <esben@geanix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/ethernet/xilinx/ll_temac_main.c15
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c b/drivers/net/ethernet/xilinx/ll_temac_main.c
index bccef30bf64e..1003ee14c833 100644
--- a/drivers/net/ethernet/xilinx/ll_temac_main.c
+++ b/drivers/net/ethernet/xilinx/ll_temac_main.c
@@ -314,17 +314,21 @@ static int temac_dma_bd_init(struct net_device *ndev)
CHNL_CTRL_IRQ_EN | CHNL_CTRL_IRQ_ERR_EN |
CHNL_CTRL_IRQ_DLY_EN | CHNL_CTRL_IRQ_COAL_EN);
- lp->dma_out(lp, RX_CURDESC_PTR, lp->rx_bd_p);
- lp->dma_out(lp, RX_TAILDESC_PTR,
- lp->rx_bd_p + (sizeof(*lp->rx_bd_v) * (RX_BD_NUM - 1)));
- lp->dma_out(lp, TX_CURDESC_PTR, lp->tx_bd_p);
-
/* Init descriptor indexes */
lp->tx_bd_ci = 0;
lp->tx_bd_next = 0;
lp->tx_bd_tail = 0;
lp->rx_bd_ci = 0;
+ /* Enable RX DMA transfers */
+ wmb();
+ lp->dma_out(lp, RX_CURDESC_PTR, lp->rx_bd_p);
+ lp->dma_out(lp, RX_TAILDESC_PTR,
+ lp->rx_bd_p + (sizeof(*lp->rx_bd_v) * (RX_BD_NUM - 1)));
+
+ /* Prepare for TX DMA transfer */
+ lp->dma_out(lp, TX_CURDESC_PTR, lp->tx_bd_p);
+
return 0;
out:
@@ -789,6 +793,7 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
skb_tx_timestamp(skb);
/* Kick off the transfer */
+ wmb();
lp->dma_out(lp, TX_TAILDESC_PTR, tail_p); /* DMA start */
return NETDEV_TX_OK;