@@ -30,6 +30,7 @@
#include <linux/ipv6.h>
#include <asm/unaligned.h>
#include <net/ip6_checksum.h>
+#include <net/netdev_queues.h>
#include "r8169.h"
#include "r8169_firmware.h"
@@ -68,6 +69,8 @@
#define NUM_RX_DESC 256 /* Number of Rx descriptor registers */
#define R8169_TX_RING_BYTES (NUM_TX_DESC * sizeof(struct TxDesc))
#define R8169_RX_RING_BYTES (NUM_RX_DESC * sizeof(struct RxDesc))
+#define R8169_TX_STOP_THRS (MAX_SKB_FRAGS + 1)
+#define R8169_TX_START_THRS (2 * R8169_TX_STOP_THRS)
#define OCP_STD_PHY_BASE 0xa400
@@ -4162,13 +4165,9 @@ static bool rtl8169_tso_csum_v2(struct rtl8169_private *tp,
return true;
}
-static bool rtl_tx_slots_avail(struct rtl8169_private *tp)
+static unsigned int rtl_tx_slots_avail(struct rtl8169_private *tp)
{
- unsigned int slots_avail = READ_ONCE(tp->dirty_tx) + NUM_TX_DESC
- - READ_ONCE(tp->cur_tx);
-
- /* A skbuff with nr_frags needs nr_frags+1 entries in the tx queue */
- return slots_avail > MAX_SKB_FRAGS;
+ return READ_ONCE(tp->dirty_tx) + NUM_TX_DESC - READ_ONCE(tp->cur_tx);
}
/* Versions RTL8102e and from RTL8168c onwards support csum_v2 */
@@ -4245,27 +4244,10 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb,
WRITE_ONCE(tp->cur_tx, tp->cur_tx + frags + 1);
- stop_queue = !rtl_tx_slots_avail(tp);
- if (unlikely(stop_queue)) {
- /* Avoid wrongly optimistic queue wake-up: rtl_tx thread must
- * not miss a ring update when it notices a stopped queue.
- */
- smp_wmb();
- netif_stop_queue(dev);
- /* Sync with rtl_tx:
- * - publish queue status and cur_tx ring index (write barrier)
- * - refresh dirty_tx ring index (read barrier).
- * May the current thread have a pessimistic view of the ring
- * status and forget to wake up queue, a racing rtl_tx thread
- * can't.
- */
- smp_mb__after_atomic();
- if (rtl_tx_slots_avail(tp))
- netif_start_queue(dev);
- door_bell = true;
- }
-
- if (door_bell)
+ stop_queue = !netif_subqueue_maybe_stop(dev, 0, rtl_tx_slots_avail(tp),
+ R8169_TX_STOP_THRS,
+ R8169_TX_START_THRS);
+ if (door_bell || stop_queue)
rtl8169_doorbell(tp);
return NETDEV_TX_OK;
@@ -4400,7 +4382,8 @@ static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp,
* ring status.
*/
smp_store_mb(tp->dirty_tx, dirty_tx);
- if (netif_queue_stopped(dev) && rtl_tx_slots_avail(tp))
+ if (netif_queue_stopped(dev) &&
+ rtl_tx_slots_avail(tp) >= R8169_TX_START_THRS)
netif_wake_queue(dev);
/*
* 8168 hack: TxPoll requests are lost when the Tx packets are
Use new net core macro netif_subqueue_maybe_stop in the start_xmit path to simplify the code. Whilst at it, set the tx queue start threshold to twice the stop threshold. Before values were the same, resulting in stopping/starting the queue more often than needed. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> --- v2: - ring doorbell if queue was stopped v3: - remove change log from commit message --- drivers/net/ethernet/realtek/r8169_main.c | 39 +++++++---------------- 1 file changed, 11 insertions(+), 28 deletions(-)