Hi!
Recently I was playing with using my HID device differently then usual: I used the libusb library. Instead opening a raw file /dev/hidraw1, I used libusb_open_device_with_vid_pid().
Everything was working properly, then it was a time to go back using the hidraw file… but wait: where is my hidraw1 device?
It seems it was gone since I opened it with libusb:
# ll /dev/hidraw* crw------- 1 root 0 247, 0 Oct 19 18:49 /dev/hidraw0 crw------- 1 root 0 247, 2 Jan 1 1970 /dev/hidraw2 crw------- 1 root 0 247, 3 Jan 1 1970 /dev/hidraw3
As you can see – hidraw1 is missing.
Fortunately I found a solution to this issue which I am now sharing here (also for me).
When I typed lsusb -t to list all my devices I’ve got:
# lsusb -t
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=dwc_otg/1p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/3p, 480M
|__ Port 1: Dev 3, If 0, Class=Vendor Specific Class, Driver=smsc95xx, 480M
|__ Port 3: Dev 4, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 2: Dev 5, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 4: Dev 7, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 4: Dev 9, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M
|__ Port 4: Dev 9, If 1, Class=Human Interface Device, Driver=usbhid, 1.5M
|__ Port 3: Dev 123, If 1, Class=CDC Data, Driver=cdc_acm, 12M
|__ Port 3: Dev 123, If 2, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 3: Dev 123, If 0, Class=Communications, Driver=cdc_acm, 12M
|__ Port 4: Dev 8, If 0, Class=Human Interface Device, Driver=usbfs, 1.5M
The device which I want back is in the last line. Note the Driver=usbfs. This is the key part – the device is bound to usbfs driver instead of usbhid.
I had to unbind the device from usbfs driver and bind back to usbhid.
To do it I entered /sys/bus/usb/drivers/usbfs and typed:
/sys/bus/usb/drivers/usbfs # ls -la total 0 drwxr-xr-x 2 root 0 0 Oct 23 18:35 . drwxr-xr-x 9 root 0 0 Oct 23 18:35 .. lrwxrwxrwx 1 root 0 0 Oct 23 18:42 1-1.3.4:1.0 -> ../../../../devices/platform/soc/20980000.usb/usb1/1-1/1-1.3/1-1.3.4/1-1.3.4:1.0 --w------- 1 root 0 4096 Oct 23 18:42 bind lrwxrwxrwx 1 root 0 0 Oct 23 18:42 module -> ../../../../module/usbcore -rw-r--r-- 1 root 0 4096 Oct 23 18:42 new_id -rw-r--r-- 1 root 0 4096 Oct 23 18:42 remove_id --w------- 1 root 0 4096 Oct 23 18:42 uevent --w------- 1 root 0 4096 Oct 23 18:42 unbind
As you can see the device “1-1.3.4:1.0” (you can correlate this path with lsusb -t) is listed here (bound).
I typed:
/sys/bus/usb/drivers/usbfs # echo -n "1-1.3.4:1.0" > unbind sh: write error: No such device
Despite this error when I looked again the device is not bind there anymore:
/sys/bus/usb/drivers/usbfs # ls -la total 0 drwxr-xr-x 2 root 0 0 Oct 23 18:35 . drwxr-xr-x 9 root 0 0 Oct 23 18:35 .. --w------- 1 root 0 4096 Oct 23 18:42 bind lrwxrwxrwx 1 root 0 0 Oct 23 18:42 module -> ../../../../module/usbcore -rw-r--r-- 1 root 0 4096 Oct 23 18:42 new_id -rw-r--r-- 1 root 0 4096 Oct 23 18:42 remove_id --w------- 1 root 0 4096 Oct 23 18:42 uevent --w------- 1 root 0 4096 Oct 23 18:44 unbind
Now it was a time to bound it to usbhid (first typing cd ../usbhid):
/sys/bus/usb/drivers/usbhid # ll total 0 drwxr-xr-x 2 root 0 0 Oct 23 18:35 . drwxr-xr-x 9 root 0 0 Oct 23 18:35 .. lrwxrwxrwx 1 root 0 0 Oct 23 18:35 1-1.3.2.4.4:1.0 -> ../../../../devices/platform/soc/20980000.usb/usb1/1-1/1-1.3/1-1.3.2/1-1.3.2.4/1-1.3.2.4.4/1-1.3.2.4.4:1.0 lrwxrwxrwx 1 root 0 0 Oct 23 18:35 1-1.3.2.4.4:1.1 -> ../../../../devices/platform/soc/20980000.usb/usb1/1-1/1-1.3/1-1.3.2/1-1.3.2.4/1-1.3.2.4.4/1-1.3.2.4.4:1.1 lrwxrwxrwx 1 root 0 0 Oct 23 18:35 1-1.3.3:1.2 -> ../../../../devices/platform/soc/20980000.usb/usb1/1-1/1-1.3/1-1.3.3/1-1.3.3:1.2 --w------- 1 root 0 4096 Oct 23 18:35 bind lrwxrwxrwx 1 root 0 0 Oct 23 18:35 module -> ../../../../module/usbhid -rw-r--r-- 1 root 0 4096 Oct 23 18:35 new_id -rw-r--r-- 1 root 0 4096 Oct 23 18:35 remove_id --w------- 1 root 0 4096 Oct 23 18:35 uevent --w------- 1 root 0 4096 Oct 23 18:35 unbind /sys/bus/usb/drivers/usbhid # echo -n "1-1.3.4:1.0" > bind /sys/bus/usb/drivers/usbhid # ll total 0 drwxr-xr-x 2 root 0 0 Oct 23 18:35 . drwxr-xr-x 9 root 0 0 Oct 23 18:35 .. lrwxrwxrwx 1 root 0 0 Oct 23 18:35 1-1.3.2.4.4:1.0 -> ../../../../devices/platform/soc/20980000.usb/usb1/1-1/1-1.3/1-1.3.2/1-1.3.2.4/1-1.3.2.4.4/1-1.3.2.4.4:1.0 lrwxrwxrwx 1 root 0 0 Oct 23 18:35 1-1.3.2.4.4:1.1 -> ../../../../devices/platform/soc/20980000.usb/usb1/1-1/1-1.3/1-1.3.2/1-1.3.2.4/1-1.3.2.4.4/1-1.3.2.4.4:1.1 lrwxrwxrwx 1 root 0 0 Oct 23 18:35 1-1.3.3:1.2 -> ../../../../devices/platform/soc/20980000.usb/usb1/1-1/1-1.3/1-1.3.3/1-1.3.3:1.2 lrwxrwxrwx 1 root 0 0 Oct 23 18:45 1-1.3.4:1.0 -> ../../../../devices/platform/soc/20980000.usb/usb1/1-1/1-1.3/1-1.3.4/1-1.3.4:1.0 --w------- 1 root 0 4096 Oct 23 18:45 bind lrwxrwxrwx 1 root 0 0 Oct 23 18:35 module -> ../../../../module/usbhid -rw-r--r-- 1 root 0 4096 Oct 23 18:35 new_id -rw-r--r-- 1 root 0 4096 Oct 23 18:35 remove_id --w------- 1 root 0 4096 Oct 23 18:35 uevent --w------- 1 root 0 4096 Oct 23 18:35 unbind
And I’ve got back my missing hidraw1 device:
~ # ll /dev/hidraw* crw------- 1 root 0 247, 0 Oct 19 18:49 /dev/hidraw0 crw------- 1 root 0 247, 1 Oct 23 18:45 /dev/hidraw1 crw------- 1 root 0 247, 2 Jan 1 1970 /dev/hidraw2 crw------- 1 root 0 247, 3 Jan 1 1970 /dev/hidraw3
The driver change is also confirmed in ‘lsusb -t‘:
# lsusb -t
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=dwc_otg/1p, 480M
|__ Port 1: Dev 2, If 0, Class=Hub, Driver=hub/3p, 480M
|__ Port 1: Dev 3, If 0, Class=Vendor Specific Class, Driver=smsc95xx, 480M
|__ Port 3: Dev 4, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 2: Dev 5, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 4: Dev 7, If 0, Class=Hub, Driver=hub/4p, 480M
|__ Port 4: Dev 9, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M
|__ Port 4: Dev 9, If 1, Class=Human Interface Device, Driver=usbhid, 1.5M
|__ Port 3: Dev 123, If 1, Class=CDC Data, Driver=cdc_acm, 12M
|__ Port 3: Dev 123, If 2, Class=Human Interface Device, Driver=usbhid, 12M
|__ Port 3: Dev 123, If 0, Class=Communications, Driver=cdc_acm, 12M
|__ Port 4: Dev 8, If 0, Class=Human Interface Device, Driver=usbhid, 1.5M