From: Heiner Kallweit Date: Thu, 29 Oct 2020 17:56:06 +0000 (+0100) Subject: r8169: remove unneeded memory barrier in rtl_tx X-Git-Tag: v5.11-rc1~169^2~404 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3a689e34973e8717cd57991c6fcf527dc56062b5;p=thirdparty%2Fkernel%2Flinux.git r8169: remove unneeded memory barrier in rtl_tx tp->dirty_tx isn't changed outside rtl_tx(). Therefore I see no need to guarantee a specific order of reading tp->dirty_tx and tp->cur_tx. Having said that we can remove the memory barrier. In addition use READ_ONCE() when reading tp->cur_tx because it can change in parallel to rtl_tx(). Signed-off-by: Heiner Kallweit Link: https://lore.kernel.org/r/2264563a-fa9e-11b0-2c42-31bc6b8e2790@gmail.com Signed-off-by: Jakub Kicinski --- diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c index b6c11aaa55b1d..75df476c6f7bd 100644 --- a/drivers/net/ethernet/realtek/r8169_main.c +++ b/drivers/net/ethernet/realtek/r8169_main.c @@ -4364,9 +4364,8 @@ static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp, unsigned int dirty_tx, tx_left, bytes_compl = 0, pkts_compl = 0; dirty_tx = tp->dirty_tx; - smp_rmb(); - for (tx_left = tp->cur_tx - dirty_tx; tx_left > 0; tx_left--) { + for (tx_left = READ_ONCE(tp->cur_tx) - dirty_tx; tx_left; tx_left--) { unsigned int entry = dirty_tx % NUM_TX_DESC; struct sk_buff *skb = tp->tx_skb[entry].skb; u32 status;