netdev - [PATCH net-next 4/4] r8169: remove now unneeded barrier in rtl

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Message-ID: <855fccd1-86d4-7f02-b202-a7e0240e677e@gmail.com>
Date:   Fri, 6 Mar 2020 23:58:50 +0100
From:   Heiner Kallweit <hkallweit1@...il.com>
To:     Realtek linux nic maintainers <nic_swsd@...ltek.com>,
        David Miller <davem@...emloft.net>
Cc:     "netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: [PATCH net-next 4/4] r8169: remove now unneeded barrier in rtl_tx

Until ae84bc187337 ("r8169: don't use bit LastFrag in tx descriptor
after send") we used to access another bit in the descriptor, therefore
it seems the barrier was needed. Since this commit DescOwn is the
only bit we're interested in, so the barrier isn't needed any longer.

Signed-off-by: Heiner Kallweit <hkallweit1@...il.com>
---
 drivers/net/ethernet/realtek/r8169_main.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index 8a707d67c..181b35b78 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -4397,12 +4397,6 @@ static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp,
 		if (status & DescOwn)
 			break;
 
-		/* This barrier is needed to keep us from reading
-		 * any other fields out of the Tx descriptor until
-		 * we know the status of DescOwn
-		 */
-		dma_rmb();
-
 		rtl8169_unmap_tx_skb(tp, entry);
 
 		if (skb) {
-- 
2.25.1