Advanced USB discovery with usb-devices
If you’re working with USB devices a lot, Linux platform offers a great way to learn more about what you have connected to your system: usb-devices command.
Using usb-devices Command
Simply type usb-devices and enjoy the output. Below is an example from one of my virtual machines:
greys@mint:~ $ usb-devices T: Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=480 MxCh=15 D: Ver= 2.00 Cls=09(hub ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 P: Vendor=1d6b ProdID=0002 Rev=04.15 S: Manufacturer=Linux 4.15.0-54-generic ehci_hcd S: Product=EHCI Host Controller S: SerialNumber=0000:00:1d.7 C: #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=0mA I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub T: Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 6 Spd=480 MxCh= 0 D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 P: Vendor=203a ProdID=fffa Rev=01.00 S: Manufacturer=Parallels S: Product=Virtual Printer (Print to PDF (Mac Desktop)) S: SerialNumber=TAG11d87aca0 C: #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr=0mA I: If#= 0 Alt= 0 #EPs= 1 Cls=07(print) Sub=01 Prot=01 Driver=usblp T: Bus=01 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#= 9 Spd=480 MxCh= 0 D: Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 P: Vendor=203a ProdID=fffa Rev=01.00 S: Manufacturer=Parallels S: Product=Virtual Printer (Brother HL-L5200DW series) S: SerialNumber=TAG1c8860e8b C: #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr=0mA I: If#= 0 Alt= 0 #EPs= 1 Cls=07(print) Sub=01 Prot=01 Driver=usblp
Understanding usb-devices Output
There’s a lot of information there, but almost every line is useful.
First line confirms USB port location – system bus and port on it. It’s also a great way of seeing the speed of the port – 480Mbit suggests it’s a USB2 port:
T: Bus=01 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#= 9 Spd=480 MxCh= 0
There’s a few lines documenting the device manufacturer and model name. Because it’s a virtual machine running on my Parallels Desktop software, manufacturer is reported as Parallels. But next line clarifies that this is actually the Brother laser printer from my home office network:
S: Manufacturer=Parallels S: Product=Virtual Printer (Brother HL-L5200DW series)
There’s a line that I imagine will be more useful on laptops, reporting the power consumption reported for this USB port:
C: #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr=0mA
And last, but not least, is the line confirming device driver responsible for functionality of the USB device – should be very handy for troubleshooting:
I: If#= 0 Alt= 0 #EPs= 1 Cls=07(print) Sub=01 Prot=01 Driver=usblp
I’ll run this usb-devices command on my Dell XPS laptop with Ubuntu 19.10 soon and will share my findings.