From f32bfb9a8ca083f8d148ea90ae5ba66f4831836e Mon Sep 17 00:00:00 2001 From: Sergei Shtylyov Date: Tue, 3 Nov 2015 22:36:04 +0300 Subject: [PATCH 1/1] sh_eth: use DMA barriers Commit 7d7355f58ba4 ("sh_eth: Ensure proper ordering of descriptor active bit write/read") did the right thing but used too "heavy" barriers while there were already "lighter" DMA barriers exactly for this case... Signed-off-by: Sergei Shtylyov Signed-off-by: David S. Miller --- drivers/net/ethernet/renesas/sh_eth.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c index dc5d34e1d01e..6150a235b72c 100644 --- a/drivers/net/ethernet/renesas/sh_eth.c +++ b/drivers/net/ethernet/renesas/sh_eth.c @@ -1416,7 +1416,7 @@ static int sh_eth_txfree(struct net_device *ndev) if (txdesc->status & cpu_to_edmac(mdp, TD_TACT)) break; /* TACT bit must be checked before all the following reads */ - rmb(); + dma_rmb(); netif_info(mdp, tx_done, ndev, "tx entry %d status 0x%08x\n", entry, edmac_to_cpu(mdp, txdesc->status)); @@ -1458,7 +1458,7 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status, int *quota) rxdesc = &mdp->rx_ring[entry]; while (!(rxdesc->status & cpu_to_edmac(mdp, RD_RACT))) { /* RACT bit must be checked before all the following reads */ - rmb(); + dma_rmb(); desc_status = edmac_to_cpu(mdp, rxdesc->status); pkt_len = rxdesc->frame_length; @@ -1544,7 +1544,7 @@ static int sh_eth_rx(struct net_device *ndev, u32 intr_status, int *quota) skb_checksum_none_assert(skb); rxdesc->addr = dma_addr; } - wmb(); /* RACT bit must be set after all the above writes */ + dma_wmb(); /* RACT bit must be set after all the above writes */ if (entry >= mdp->num_rx_ring - 1) rxdesc->status |= cpu_to_edmac(mdp, RD_RACT | RD_RFP | RD_RDLE); @@ -2403,7 +2403,7 @@ static int sh_eth_start_xmit(struct sk_buff *skb, struct net_device *ndev) } txdesc->buffer_length = skb->len; - wmb(); /* TACT bit must be set after all the above writes */ + dma_wmb(); /* TACT bit must be set after all the above writes */ if (entry >= mdp->num_tx_ring - 1) txdesc->status |= cpu_to_edmac(mdp, TD_TACT | TD_TDLE); else -- 2.39.2