Comment 6 for bug 1926809

I used the mainline tool to install kernel 5.12.

The dock is back again and everything appears to work.

```
mulhollandd@mulhollandd-XPS-13-9360:~$ uname -a
Linux mulhollandd-XPS-13-9360 5.12.0-051200-generic #202104252130 SMP Sun Apr 25 21:33:13 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux
mulhollandd@mulhollandd-XPS-13-9360:~$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 21.04
Release: 21.04
Codename: hirsute
mulhollandd@mulhollandd-XPS-13-9360:~$ sudo dmesg --level=err
[sudo] password for mulhollandd:
[ 0.011338] efi: Failed to lookup EFI memory descriptor for 0x000000007b014000
[ 14.615560] xhci_hcd 0000:39:00.0: xHCI host controller not responding, assume dead
[ 14.615574] xhci_hcd 0000:39:00.0: HC died; cleaning up
[ 15.030088] usb 4-1.3: device not accepting address 3, error -108
[ 15.030150] usb 4-1-port3: couldn't allocate usb_device
[ 15.030198] usb 3-1-port5: couldn't allocate usb_device
[ 112.758908] [drm:drm_dp_send_dpcd_read [drm_kms_helper]] *ERROR* mstb 00000000b3a810eb port 3: DPCD read on addr 0x4b0 for 1 bytes NAKed
mulhollandd@mulhollandd-XPS-13-9360:~$
```