From 73f7375d3ed6ad372f1e9404007a0c866063d773 Mon Sep 17 00:00:00 2001 From: Esben Haabendal Date: Tue, 30 Apr 2019 09:17:59 +0200 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- drivers/net/ethernet/xilinx/ll_temac_main.c | 15 ++++++++++----- 1 file 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; -- 2.11.0