Hi, I noticed that the usb ethernet gadget driver is broken since v5.5-rc2 and 5.4.4, but only for our OMAP5 board. Our OMAP3 boards work with the same tree, kernel binary and user-space (Debian Stretch).
The symptom is that I can see the interface on the host PC being enumerated and IP addresses etc. are set up. But a ping in either direction fails/times out.
After inspecting diffs I found some changes in dwc3:gadget and indeed omap3/twl4030 uses musb and omap5 uses dwc3.
Reverting
a7f7e61270f1 ("usb: dwc3: gadget: Fix logical condition");
on v5.5-rc makes it work again.
BTW: v4.19.90 works although it includes this logical condition fix. So the real difference between v4.19 and v5.5 may be elsewhere in newer kernels and only be revealed by the patch.
If important: my setup is running with USB2 cable and speed only.
So please check this and other recent dwc3 patches for introducing a stall of communication.
BR and thanks, Nikolaus Schaller