I think you may be experiencing a similar issue to myself and @kross which seems to have arrived a week ago after a major update to the RPi software which upgraded the linux kernel from version 4.19 to 5.4. Until then I had been using my RPi with a tp-link 7-port powered USB3.0 hub with five of its ports occupied. I use the RPi’s USB3.0 port to feed it, and the second USB3.0 port to connect to an SSD which is my boot device. I follow @dmsummers advice and avoid 2.4GHZ wifi. Fortunately I am now back to full functionality after carefully monitoring the USB list of devices (using lsusb in a terminal window) to ensure that all devices are present. In my case if I connect a Pegasus Astro PPB with its FTDI serial port adapter inside to the end port of the hub all list entries on Bus 001 (the USB 2.0 bus) disappear. The same device plugged in further along the hub and a reboot and everything works.again.
mhammady wrote: Hi,
I need 5 USB ports (to use the new filter wheel), but RPi has only 4. I tried to use an old USB hub but didn't work. I purchased a new powered USB hub but also I couldn't see the devices used by the hub.
Any idea what is the correct solution for using a USB HUB with RPi 4?
dmsummers wrote: You don't state whether you are using wireless or ethernet (and 2.4Ghz or 5Ghz if wireless). The safest bet (slower but more stable) is to start your tests by running your powered hub data cable to the PI4 USB2 port (NOT the PI4 USB3 port just yet).
dallmon wrote: mhammady,
I would check the USB cable you have between the Pi and the hub.
I'm using 5 USB-2 peripherals - 4 on an unpowered hub and one on the RPi directly, and one USB-3 for a. little SSD, and have also run a USB-3 hub, but with USB-2 peripherals. It all works, and I don't recall doing anything special. I had a bad cable at one point.
Bus 001 Device 004: ID 05e3:0610 Genesys Logic, Inc. 4-port hub Bus 001 Device 003: ID 05e3:0610 Genesys Logic, Inc. 4-port hub Bus 001 Device 002: ID 2109:3431 VIA Labs, Inc. Hub Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub