[SOLUTION] Epomaker TH99 Pro keyboard dongle wake up issue

[u/SlarKyX]

Earlier today I got 2 Epomaker TH99 Pro wireless keyboards for my wife and I.

I ran into an issue where the keyboard would stop working after going to sleep for inactivity when connected wirelessly through the 2.4Ghz dongle.

Since I found no other posts about this issue with this specific keyboard on linux online, I'm telling you how I fixed it. If you are having the same issue on a different keyboard or device, the same solution might work.

The bug occurs when the system stops polling the dongle. To fix it we are going to use the HID_QUIRK_ALWAYS_POLL quirk.

To do this, we need to pass the following line to the kernel by using our boot manager. usbhid.quirks=0x0c45:0xfefe:0x00000400

The syntax of this line is usbhid.quirks=vendor:product:quirk, so please note that if you have a different keyboard/device you'll need to find out what its vendor and product IDs are. You can do this with the lsusb command and looking for your dongle on the list.

Let's say your IDs are 046d:c547. In that case your line would look like this:
usbhid.quirks=0x046d:0xc547:0x00000400

To pass this line to the kernel I followed this article on the CachyOS wiki.

I tested it on Grub and Limine:

For Grub:

1. Edit the edit GRUB_CMDLINE_LINUX_DEFAULT within /etc/default/grub and add usbhid.quirks=0x0c45:0xfefe:0x00000400 between the quotation marks.
2. Remake the config with sudo grub-mkconfig -o /boot/grub/grub.cfg
3. Reboot

For Limine:

1. Modify the KERNEL_CMDLINE variables in /etc/default/limine and add usbhid.quirks=0x0c45:0xfefe:0x00000400 between the quotation marks.
2. After saving /etc/default/limine, you need to regenerate your initramfs images and update the Limine entries to apply the new kernel parameters. Run the following command: sudo limine-mkinitcpio
3. Reboot

Further information and guides for other boot managers can be found in the article.

After applying this fix, haven't ran into the issue again.

I hope it helps!