[openwrt/openwrt] ar71xx: only access device stats in tx handler if packets were processed

[LEDE Commits]

nbd pushed a commit to openwrt/openwrt.git, branch master:
https://git.lede-project.org/31e6016d2e41199b22577b429b8691526a4359f6

commit 31e6016d2e41199b22577b429b8691526a4359f6
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Tue Dec 5 14:23:59 2017 +0100

    ar71xx: only access device stats in tx handler if packets were processed
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 .../ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c  | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c
index e8eb632..72e6b32 100644
--- a/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c
+++ b/target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c
@@ -999,12 +999,12 @@ static int ag71xx_tx_packets(struct ag71xx *ag, bool flush)
 
 	DBG("%s: %d packets sent out\n", ag->dev->name, sent);
 
-	ag->dev->stats.tx_bytes += bytes_compl;
-	ag->dev->stats.tx_packets += sent;
-
 	if (!sent)
 		return 0;
 
+	ag->dev->stats.tx_bytes += bytes_compl;
+	ag->dev->stats.tx_packets += sent;
+
 	netdev_completed_queue(ag->dev, sent, bytes_compl);
 	if ((ring->curr - ring->dirty) < (ring_size * 3) / 4)
 		netif_wake_queue(ag->dev);