> From: Archimedes Gaviola <archimedes.gavi...@gmail.com> > Date: Tue, 6 Oct 2020 19:24:34 +0800 > > Hi, > > I plugged my USB (bus powered) vacuum fluorescent display (VFD) pole device > and detected as uplcom(4) driver. After the device has been detected kernel > panic was observed or freezes the whole system. Please see attached > screenshot https://i.postimg.cc/sXSJyc4S/IMG-7820.jpg and dmesg for > details. > > For now, the only way to prevent the issue is to shutdown my Raspberry Pi > 4B system and then plug the VFD device. There is no problem with > OpenBSD-6.7 i386 release, plug and play works as expected. > > uplcom0 at uhub2 port 4 configuration 1 interface 0 "Prolific Technology > Inc. USB-Serial Controller" rev 2.00/3.00 addr 7 > ucom0 at uplcom0 > > Hardware: Raspberry Pi 4B > UEFI Firmware: UEFI v1.18 > OpenBSD-current (arm64): August 27, 2020 > > Thanks and best regards, > Archimedes
Judging from your description of the device and the "impossible" panic, I suspect this is a power issue. The crash is typical for situations where the voltage to the CPU and/or memory drops too low. A better power supply might help, but it may be best to use an externally powered USB hub instead.
