We are using Imx6q for our custom product where we have USB to Ethernet (SMSC95xx) interface.
While testing using iperf above 20Mbps, and we connect disconnect device (USB cellular modem or Webcam etc) on any other USB ports, we see packet drops on iperf testing.
This drops are in incoming iperf flows (USB Rx) only and not on outgoing flow (USB Tx).
Can you advise what can be the issue?
I feel this could be USB interrupts handling issue so I tried to set smp_affinity for USB interrupts to all 4 CPUs but I can set only 1 CPU at a time.
We are very near to product launch.
Please advise if any errata (and workaround if any).