USB Debugfs

To Get Information of Hubs and Devices

You can use USB debugfs to get the information of the USB hubs and devices.

The following code block provides an example.
mount -t debugfs none /sys/kernel/debug
cd /sys/kernel/debug/usb
cat devices

To Get Information of Root Hub

You can use USB debugfs to get information of the USB root hub.

The following code block provides an example for USB2.0.
T:  Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=480  MxCh= 1 
B:  Alloc=  0/800 us ( 0%), #Int=  0, #Iso=  0
D:  Ver= 2.00 Cls=09(hub  ) Sub=00 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=1d6b ProdID=0002 Rev= 5.15
S:  Manufacturer=Linux 5.15.79-dirty xhci-hcd
S:  Product=xHCI Host Controller
S:  SerialNumber=xhci-hcd.1.auto
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
E:  Ad=81(I) Atr=03(Int.) MxPS=   4 Ivl=256ms
The following code block provides an example for USB3.0.
T:  Bus=02 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=5000 MxCh= 1
B:  Alloc=  0/800 us ( 0%), #Int=  0, #Iso=  0
D:  Ver= 3.00 Cls=09(hub  ) Sub=00 Prot=03 MxPS= 9 #Cfgs=  1
P:  Vendor=1d6b ProdID=0003 Rev= 5.15
S:  Manufacturer=Linux 5.15.79-dirty xhci-hcd
S:  Product=xHCI Host Controller
S:  SerialNumber=xhci-hcd.1.auto
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
E:  Ad=81(I) Atr=03(Int.) MxPS=   4 Ivl=256ms

To Get Information of Attached Devices

You can use USB debugfs to get information of the USB attached devices.

The following code block provides an example of getting information of an attached Kingston SSD mass storage device.
T:  Bus=02 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  5 Spd=5000 MxCh= 0
D:  Ver= 3.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 9 #Cfgs=  1
P:  Vendor=174c ProdID=55aa Rev= 1.00
S:  Manufacturer=asmedia
S:  Product=ASM1153E
S:  SerialNumber=00000000000000000000
C:* #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr=  0mA
I:  If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=uas
E:  Ad=81(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
I:* If#= 0 Alt= 1 #EPs= 4 Cls=08(stor.) Sub=06 Prot=62 Driver=uas
E:  Ad=81(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E:  Ad=83(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E:  Ad=04(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms