Re: [regression 6.12.y] After backport of 980084de4d9b ("Bluetooth: btusb: Add ASUS USB-BT540 for Realtek 8761CU") bluethooth not anymore working on 0b05:1bef ASUSTek Computer, Inc. Bluetooth Controller (requests firmware)

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Sat, Oct 24, 2026 at 04:10:59PM -0400, Sasha Levin wrote:
> > I did meanwhile and agree, the backports of these should be reverted
> > from 6.18.y and 6.12.y:
> >
> > * 980084de4d9b25 ("Bluetooth: btusb: Add ASUS USB-BT540 for Realtek
> > 8761CU") [v7.3-rc1]
> > * 6f0624b4427e38 ("Bluetooth: btusb: Add ASUS USB-BT600 for Realtek
> > 8761CU") [v7.3-rc1]
> > * 4a23ce935f74d1 ("Bluetooth: btrtl: Add the support for RTL8761CUV")
> > [v6.19-rc1]
> 
> The stable trees match mainline here, so nothing is going into stable for
> this. The fix has to come from the Bluetooth maintainers or Christoph: an
> upstream revert of the ID commits, or a fallback to the ROM firmware when
> rtl8761cu_fw.bin is missing. Stable will take either one for 7.2, 6.18 and
> 6.12 through the normal Cc: stable route once it is in mainline.
> 
> The other way out is on the distro side. rtl_bt/rtl8761cu_fw.bin has been in
> linux-firmware since 20251111, so a newer firmware-realtek package fixes this
> without any kernel change.

That's the simplest solution, any users hitting this should also upgrade
that package as it's been out for almost a year now.

thanks,

greg k-h