Disable IRQ coalescing as it seems to not work properly in our
port because at some point triggering interrupts stops altogether.
In this case the netperf tests produce around 0.1(!) MBit/s of
throughput.
--- src/linux/drivers/net/ethernet/realtek/r8169_main.c
+++ src/linux/drivers/net/ethernet/realtek/r8169_main.c
@@ -5374,7 +5374,7 @@
 	dev->hw_features |= NETIF_F_RXALL;
 	dev->hw_features |= NETIF_F_RXFCS;
 
-	netdev_sw_irq_coalesce_default_on(dev);
+	// netdev_sw_irq_coalesce_default_on(dev);
 
 	/* configure chip for default features */
 	rtl8169_set_features(dev, dev->features);