New ubuntu 18.04 installation - wireless dongle issue

[chili555]

What is the exact response to the terminal commands:

modinfo 8821cu | grep C811
sudo modprobe 8821cu && dmesg | grep 8821

[riggster]

ryan@LinuxBox1:~$ modinfo 8821cu | grep C811
alias: usb:v0BDApC811d*dc*dsc*dp*icFFiscFFipFFin*
ryan@LinuxBox1:~$ sudo modprobe 8821cu && dmesg | grep 8821
[sudo] password for ryan:
[ 9211.745460] 8821cu: loading out-of-tree module taints kernel.
[ 9211.745926] 8821cu: module verification failed: signature and/or required key missing - tainting kernel
[ 9211.749680] usbcore: registered new interface driver rtl8821cu

[chili555]

The driver loads without complaint and is verified to cover your device. Did you try a reboot? Did you try removing and reinserting the device? It ought to take off like a rocket!

Please run:

tail -f /var/log/syslog

Remove and reinsert the device. Note and post the resultant text.

Get out of 'tail' with Ctrl+c.

[riggster]

rebooting didn't help. unplugging and plugging didn't help. Here is the output from that tail command you gave me.

ryan@LinuxBox1:~$ tail -f /var/log/syslog
May 20 17:17:01 LinuxBox1 CRON[7161]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
May 20 17:46:01 LinuxBox1 gnome-software[2653]: no app for changed ubuntu-dock@ubuntu.com
May 20 17:46:01 LinuxBox1 gnome-software[2653]: no app for changed ubuntu-appindicators@ubuntu.com
May 20 17:46:01 LinuxBox1 gvfsd-metadata[3282]: g_udev_device_has_property: assertion 'G_UDEV_IS_DEVICE (device)' failed
May 20 17:46:01 LinuxBox1 gvfsd-metadata[3282]: g_udev_device_has_property: assertion 'G_UDEV_IS_DEVICE (device)' failed
May 20 17:46:01 LinuxBox1 gnome-shell[1867]: [AppIndicatorSupport-DEBUG] Registering StatusNotifierItem :1.78/org/ayatana/NotificationItem/software_update_available
May 20 17:46:01 LinuxBox1 kernel: [84071.154836] ISO 9660 Extensions: Microsoft Joliet Level 3
May 20 17:46:01 LinuxBox1 kernel: [84071.156566] ISOFS: changing to secondary root
May 20 17:46:01 LinuxBox1 systemd[1]: Started Clean the /media/ryan/Realtek1 mount point.
May 20 17:46:01 LinuxBox1 udisksd[855]: Mounted /dev/sr1 at /media/ryan/Realtek1 on behalf of uid 1000
May 20 17:49:33 LinuxBox1 kernel: [84283.157067] usb 2-1.8: USB disconnect, device number 7
May 20 17:49:33 LinuxBox1 systemd[1]: Unmounting /media/ryan/Realtek1...
May 20 17:49:33 LinuxBox1 udisksd[855]: Cleaning up mount point /media/ryan/Realtek1 (device 11:1 no longer exists)
May 20 17:49:33 LinuxBox1 udisksd[855]: Error cleaning up mount point /media/ryan/Realtek1: Error unmounting: Command-line `umount -l "/media/ryan/Realtek1"' exited with non-zero exit status 32: umount: /media/ryan/Realtek1: not mounted.
May 20 17:49:33 LinuxBox1 udisksd[855]: Cleaning up mount point /media/ryan/Realtek1 (device 11:1 no longer exists)
May 20 17:49:33 LinuxBox1 systemd[1]: Unmounted /media/ryan/Realtek1.
May 20 17:49:33 LinuxBox1 systemd[1]: Stopping Clean the /media/ryan/Realtek1 mount point...
May 20 17:49:33 LinuxBox1 systemd[1]: Stopped Clean the /media/ryan/Realtek1 mount point.
May 20 17:49:33 LinuxBox1 upowerd[1096]: unhandled action 'unbind' on /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.8/2-1.8:1.0
May 20 17:49:33 LinuxBox1 upowerd[1096]: unhandled action 'unbind' on /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.8
May 20 17:50:14 LinuxBox1 kernel: [84323.828206] usb 2-1.8: new high-speed USB device number 8 using ehci-pci
May 20 17:50:14 LinuxBox1 kernel: [84323.937046] usb 2-1.8: New USB device found, idVendor=0bda, idProduct=1a2b, bcdDevice= 2.00
May 20 17:50:14 LinuxBox1 kernel: [84323.937050] usb 2-1.8: New USB device strings: Mfr=1, Product=2, SerialNumber=0
May 20 17:50:14 LinuxBox1 kernel: [84323.937053] usb 2-1.8: Product: DISK
May 20 17:50:14 LinuxBox1 kernel: [84323.937055] usb 2-1.8: Manufacturer: Realtek
May 20 17:50:14 LinuxBox1 kernel: [84323.937425] usb-storage 2-1.8:1.0: USB Mass Storage device detected
May 20 17:50:14 LinuxBox1 kernel: [84323.938722] scsi host7: usb-storage 2-1.8:1.0
May 20 17:50:14 LinuxBox1 mtp-probe: checking bus 2, device 8: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.8"
May 20 17:50:14 LinuxBox1 mtp-probe: bus: 2, device: 8 was not an MTP device
May 20 17:50:14 LinuxBox1 upowerd[1096]: unhandled action 'bind' on /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.8/2-1.8:1.0
May 20 17:50:14 LinuxBox1 upowerd[1096]: unhandled action 'bind' on /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.8
May 20 17:50:15 LinuxBox1 kernel: [84324.943099] scsi 7:0:0:0: CD-ROM Realtek Driver Storage 1.00 PQ: 0 ANSI: 0 CCS
May 20 17:50:15 LinuxBox1 kernel: [84324.949290] sr 7:0:0:0: [sr1] scsi3-mmc drive: 0x/0x caddy
May 20 17:50:15 LinuxBox1 kernel: [84324.949477] sr 7:0:0:0: Attached scsi CD-ROM sr1
May 20 17:50:15 LinuxBox1 kernel: [84324.949570] sr 7:0:0:0: Attached scsi generic sg3 type 5
May 20 17:50:15 LinuxBox1 systemd[1]: media-ryan-Realtek.mount: Failed to run 'mount' task: No such file or directory
May 20 17:50:15 LinuxBox1 systemd[1]: media-ryan-Realtek.mount: Failed with result 'resources'.
May 20 17:50:15 LinuxBox1 systemd[1]: Failed to mount /media/ryan/Realtek.
May 20 17:50:16 LinuxBox1 kernel: [84325.349134] ISO 9660 Extensions: Microsoft Joliet Level 3
May 20 17:50:16 LinuxBox1 kernel: [84325.350888] ISOFS: changing to secondary root
May 20 17:50:16 LinuxBox1 systemd[1]: Started Clean the /media/ryan/Realtek1 mount point.
May 20 17:50:16 LinuxBox1 udisksd[855]: Mounted /dev/sr1 at /media/ryan/Realtek1 on behalf of uid 1000

[chili555]

All we see above is a USB key being removed and reinserted; not a USB wireless device. It identifies as:

New USB device found, idVendor=0bda, idProduct=1a2b, bcdDevice= 2.00

As you said above, your wireless is: ID 0bda:c811 Realtek Semiconductor Corp.

Just to experiment, with the device inserted, do:

sudo usb_modeswitch -KW -v 0bda -p 1a2b

What is the result?

[riggster]

Here is the output of the last command you gave me. However, I think I steered you wrong before. I was going back and forth between different forums and my terminal and gave you the wrong wireless id. When I run lsusb, I get the following for my wifi dongle:

Bus 002 Device 010: ID 0bda:1a2b Realtek Semiconductor Corp.


ryan@LinuxBox1:~/Downloads/rtl8821CU$ sudo usb_modeswitch -KW -v 0bda -p 1a2b
Take all parameters from the command line


* usb_modeswitch: handle USB devices with multiple modes
* Version 2.5.2 (C) Josua Dietze 2017
* Based on libusb1/libusbx

! PLEASE REPORT NEW CONFIGURATIONS !

DefaultVendor= 0x0bda
DefaultProduct= 0x1a2b

StandardEject=1

Look for default devices ...
found USB ID 0bda:1a2b
vendor ID matched
product ID matched
found USB ID 0781:5567
found USB ID 046d:c00e
found USB ID 8087:0024
found USB ID 1d6b:0002
found USB ID 8087:0024
found USB ID 1d6b:0002
Found devices in default mode (1)
Access device 010 on bus 002
Get the current device configuration ...
Current configuration number is 1
Use interface number 0
with class 8
Use endpoints 0x0b (out) and 0x8a (in)

USB description data (for identification)
-------------------------
Manufacturer: Realtek
Product: DISK
Serial No.: not provided
-------------------------
Sending standard EJECT sequence
Looking for active drivers ...
OK, driver detached
Set up interface 0
Use endpoint 0x0b for message sending ...
Trying to send message 1 to endpoint 0x0b ...
OK, message successfully sent
Read the response to message 1 (CSW) ...
Response successfully read (13 bytes), status 1
Trying to send message 2 to endpoint 0x0b ...
OK, message successfully sent
Read the response to message 2 (CSW) ...
Response successfully read (13 bytes), status 0
Trying to send message 3 to endpoint 0x0b ...
Sending the message returned error -1. Try to continue
Read the response to message 3 (CSW) ...
Response reading failed (error -1)
Device is gone, skip any further commands
-> Run lsusb to note any changes. Bye!

[chili555]

-> Run lsusb to note any changes. Bye!

Please do and post the result. What is the new usb.id? I suspect it is not 0bda:c811 Realtek Semiconductor Corp.

I also suspect that the driver you built is incorrect.