diff options
| author | Heiner Kallweit <hkallweit1@gmail.com> | 2020-11-12 00:56:29 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2020-11-14 03:29:07 +0300 |
| commit | ca1ab89cd2d654661f559bd83ad9fc7323cb6c86 (patch) | |
| tree | 44ec58b5f5767af3a429cf61950d2e44378303c6 | |
| parent | 95f3c5458dfa5856bb110e31d156e00d894d0134 (diff) | |
| download | linux-ca1ab89cd2d654661f559bd83ad9fc7323cb6c86.tar.xz | |
r8169: improve rtl_tx
We can simplify the for() condition and eliminate variable tx_left.
The change also considers that tp->cur_tx may be incremented by a
racing rtl8169_start_xmit().
In addition replace the write to tp->dirty_tx and the following
smp_mb() with an equivalent call to smp_store_mb(). This implicitly
adds a WRITE_ONCE() to the write.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/c2e19e5e-3d3f-d663-af32-13c3374f5def@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/ethernet/realtek/r8169_main.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c index 641c94a469c1..8910e900ec45 100644 --- a/drivers/net/ethernet/realtek/r8169_main.c +++ b/drivers/net/ethernet/realtek/r8169_main.c @@ -4362,11 +4362,11 @@ static void rtl8169_pcierr_interrupt(struct net_device *dev) static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp, int budget) { - unsigned int dirty_tx, tx_left, bytes_compl = 0, pkts_compl = 0; + unsigned int dirty_tx, bytes_compl = 0, pkts_compl = 0; dirty_tx = tp->dirty_tx; - for (tx_left = READ_ONCE(tp->cur_tx) - dirty_tx; tx_left; tx_left--) { + while (READ_ONCE(tp->cur_tx) != dirty_tx) { unsigned int entry = dirty_tx % NUM_TX_DESC; struct sk_buff *skb = tp->tx_skb[entry].skb; u32 status; @@ -4389,7 +4389,6 @@ static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp, netdev_completed_queue(dev, pkts_compl, bytes_compl); dev_sw_netstats_tx_add(dev, pkts_compl, bytes_compl); - tp->dirty_tx = dirty_tx; /* Sync with rtl8169_start_xmit: * - publish dirty_tx ring index (write barrier) * - refresh cur_tx ring index and queue status (read barrier) @@ -4397,7 +4396,7 @@ static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp, * a racing xmit thread can only have a right view of the * ring status. */ - smp_mb(); + smp_store_mb(tp->dirty_tx, dirty_tx); if (netif_queue_stopped(dev) && rtl_tx_slots_avail(tp, MAX_SKB_FRAGS)) { netif_wake_queue(dev); |