Hifive1-revB no longer connecting?


I think I might’ve busted the USB socket on my Hifive1-revB. I’ve had it working fine previously.

I’ve been busy recently so I didn’t use it for a couple months and coming back now I don’t even get a blimp in the kernel about the USB.

The device itself works from the USB port tho, it gets powered and I can also enter the “rescue” mode with blinking LED so the CPU is fine too.

There’s nothing if I reconnect the device, no loss or new device in DMESG. I tried a separate usb cable and also in Windows just to be sure (windows used to find it as well).

NOTE: I didn’t change the main program on the device since last time it worked, I’m pretty sure this is on the “connectivity” side.

Is there some other way I can connect? Any way to measure-debug the data lines on the usb socket maybe?


Turns out another machine running older Arch Linux with kernel 5.3 works fine.

I think the issue has to do with kernel 5.4 since that’s what my main machine is running (also Arch Linux, mostly identical, just updated more).


Turns out the device has some sort of usb power or timing issue and only works via a USB hub, at least on this machine.

It’s a bit odd but I got it working again via the HUB so “good enough” ™