Hi, I'm trying to certify USB on our device that is running Linux 4.14. For windows systems we were using https://www.usb.org/usb2tools. For linux the only option I have found is a kernel module called EHSET. Unfortunately I can't manage to get it working, can You please help? I have added the following configuration: CONFIG_USB_HCD_TEST_MODE=y USB_EHSET_TEST_FIXTURE=m Then on the system I type in modprobe ehset. After this looking at the source code of ehset.c I assumed that inserting USB stick with VendorID: 0x1a0a and ProductID: 0x0104 would start the Packet command, but it doesn't do anything (not output visible on the oscilloscope). The device is loaded as a regular USB stick. The output I see is: [ 1059.904034] ci_hdrc ci_hdrc.0: new USB bus registered, assigned bus number 1 [ 1059.935515] ci_hdrc ci_hdrc.0: USB 2.0 started, EHCI 1.00 [ 1059.941700] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002 [ 1059.948523] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=1 [ 1059.955776] usb usb1: Product: EHCI Host Controller [ 1059.960680] usb usb1: Manufacturer: Linux 4.14.87-rt50 ehci_hcd [ 1059.966627] usb usb1: SerialNumber: ci_hdrc.0 [ 1059.974486] usb usb1: usb_probe_device [ 1059.982387] hub 1-0:1.0: usb_probe_interface [ 1059.986735] hub 1-0:1.0: USB hub found [ 1059.990614] hub 1-0:1.0: 1 port detected [ 1060.475521] usb 1-1: new high-speed USB device number 2 using ci_hdrc [ 1060.677970] usb 1-1: New USB device found, idVendor=1a0a, idProduct=0104 [ 1060.684709] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 1060.691877] usb 1-1: Product: USB DISK 3.0 [ 1060.696005] usb 1-1: Manufacturer: [ 1060.700215] usb 1-1: SerialNumber: 190073AE389B2300 [ 1060.708279] usb 1-1: usb_probe_device [ 1060.716351] usb-storage 1-1:1.0: usb_probe_interface [ 1060.724692] usb-storage 1-1:1.0: USB Mass Storage device detected [ 1060.745330] scsi host1: usb-storage 1-1:1.0 Thanks in advance! Radek