Hi! I have a platform with DWC3 in Dual Role mode. Currently I'm experimenting on v5.12-rc5 with a few patches (mostly configuration) applied [1]. I'm using Debian Unstable on the host machine and BuildRoot with the above mentioned kernel on the target. **So, scenario 0: 1. Run iperf3 -s on target 2. Run iperf3 -c ... -t 0 on the host 3. 0.00-10.36 sec 237 MBytes 192 Mbits/sec receiver **Scenario 1: 1. Now, detach USB cable, wait for several seconds, attach it back, repeat above: 0.00-9.94 sec 209 MBytes 176 Mbits/sec receiver Note the bandwidth drop (177 vs. 192). (Repeating scenario 1 will give now the same result) **Scenario 2. 1. Detach USB cable, attach a device, for example USB stick, 2. See it being enumerated and detach it. 3. Attach cable from host 4 . 0.00-19.36 sec 315 MBytes 136 Mbits/sec receiver Note even more bandwidth drop! (Repeating scenario 1 keeps the same lower bandwidth) NOTE, sometimes on this scenario after several seconds the target simply reboots (w/o any logs [from kernel] printed)! So, any pointers on how to debug and what can be a smoking gun here? Ferry reported this in [2]. There are different kernel versions and tools to establish the connection (like connman vs. none in my case). [1]: https://github.com/andy-shev/linux/ [2]: https://github.com/andy-shev/linux/issues/31 -- With Best Regards, Andy Shevchenko
