Re: (Resolved) RTL8822CE Bluetooth Stopped Working

Post by **laprjns** » 18. Sep 2025, 13:30

FYI. My RTL8822CE Bluetooth device stopped working after upgrading to the latest kernel (5.15.193) and kernel-firmware (20250912). Reverting to the prior kernel-firmware package resolved my issue.

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rich[~]$ lspci -s 02:00
02:00.0 Network controller: Realtek Semiconductor Co., Ltd. RTL8822CE 802.11ac PCIe Wireless Network Adapter

Post by **gapan** » 18. Sep 2025, 16:07

Did the adapter disappear, or did it refuse to connect?

Post by **laprjns** » 18. Sep 2025, 18:43

When I tried running blueman-adapter from the command line, it threw the following error.

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blueman-adapters 13.09.39 ERROR    Adapter:54 __init__  : No adapter(s) found

At the time, I thought it might be related to the kernel package update. But before I reverted to the prior kernel packages, I booted the laptop into Windows 11 to see if it was a hardware issue. The Bluetooth adapter didn't seem to work there either, so I assumed it had failed and moved on to a spare Bluetooth dongle that I had lying around.
Then, this morning, I saw a post ( https://www.linuxquestions.org/question ... 75754214/ ) in the Slackware forum from someone who was having a problem with the same Bluetooth adapter (RTL8822CE) after upgrading to the latest kernel (5.15.193) and kernel-firmware (20250912). The Slackware poster resolved the issue by reverting to the prior kernel package. So, based on this, I replaced the kernel-firmware (20250912) package with kernel-firmware-20220124 and was successful in getting the adapter working again. The funny thing is that it is also working in Windows 11 now.

Post by **gapan** » 18. Sep 2025, 18:50

Wow, working/not working on windows at the same time is really weird.

Hopefully this will be fixed again in another firmware update.

Post by **laprjns** » 19. Sep 2025, 09:53

gapan wrote: ↑18. Sep 2025, 18:50 Wow, working/not working on windows at the same time is really weird.

Yeah, I don't really understand why it would have affected the Windows install. Not sure I really believe what I saw

Post by **gapan** » 19. Sep 2025, 10:32

Not sure but maybe it has to do with rebooting/cold booting. I'm thinking the firmware is uploaded to the device on boot, but not while rebooting (because it finds it's already there). So, if you rebooted to windows, the bad firmware from linux was used. If you didn't shut down the system completely before booting into windows that might have happened. I can't think if anything else really.

I guess you could test that hypothesis if you could be bothered to do so.

Post by **laprjns** » 19. Sep 2025, 13:57

Grok thinks I'm crazy, so I'm going to try and recreate it

Grok wrote:The firmware for a Realtek RTL8822 Bluetooth adapter is not persistent across reboots, even if the power to the computer is not turned off (e.g., during a soft reboot or restart). Here's a concise explanation:

- **Volatile Firmware Storage**: The RTL8822 Bluetooth adapter relies on volatile memory to hold its firmware (e.g., `rtl_bt/rtl8822b_fw.bin`). This firmware is uploaded by the host operating system's driver (Linux or Windows) during device initialization, typically at boot or when the Bluetooth subsystem starts. The adapter itself does not have non-volatile memory (like flash storage) to retain the firmware after a reboot or power cycle.

- **Reboot Behavior (With or Without Power Off)**:
- During a reboot (soft reset, where the system restarts without fully cutting power), the adapter's volatile memory is reset as part of the hardware reinitialization process. This clears the previously loaded firmware.
- When the new operating system (e.g., Windows after Linux) boots, its Bluetooth driver uploads a fresh copy of the firmware to the adapter, regardless of what was loaded before. This process is independent of the previous OS or firmware state.

- **No Persistence Across OSes**: Whether you reboot from Linux to Windows or vice versa, the firmware loaded by the previous OS is erased during the reboot. The new OS's driver will load its own firmware, assuming the correct driver and firmware files are available. The fact that power wasn't fully cut (e.g., in a soft reboot) doesn't change this, as the adapter's memory is cleared during the hardware reset.