No Bluetooth Under Kernel 7.1.0-rc3 with MediaTek MT7925

I have the same issue but with a MT7902.

This particular chipset only has support in 7.1 that I can tell. So going back to the release kernel isn’t exactly an option for my system, as with the current 7.0.6 I don’t get WiFi or BT at all. I did have to grab the firmware from the upstream linux-firmware repo to make it work at first, since there isn’t a linux-firmware-rc package that I know of.

Updated the kernel to rc3 today and no BT anymore. WiFi is still working fine.

I get the same error

FW13 kernel: Bluetooth: hci0: Failed to send wmt func ctrl (-22)

Rolled back to rc2 for now.

Not sure where to report this to.

Seems like it is at least known upstream. And there does seem to be a patch.

If anyone wants to build the CachyOS RC kernel with the patch it’s pretty simple.

Clone the CachyOS kernel repo, and drop the patch next to the pkgbuild in the linux-cachyos-rc folder. Add it to the source in the pkgbuild and run makepkg -sri

--- a/drivers/bluetooth/btmtk.c	2026-05-13 22:10:05.584145083 -0400
+++ b/drivers/bluetooth/btmtk.c	2026-05-13 22:10:47.668403231 -0400
@@ -719,8 +719,10 @@
 	case BTMTK_WMT_FUNC_CTRL:
 		if (!skb_pull_data(data->evt_skb,
 				   sizeof(wmt_evt_funcc->status))) {
-			err = -EINVAL;
-			goto err_free_skb;
+			bt_dev_dbg(hdev,
+				"FUNC_CTRL event without status, assuming UNDONE");
+			status = BTMTK_WMT_ON_UNDONE;
+			break;
 		}
 
 		wmt_evt_funcc = (struct btmtk_hci_wmt_evt_funcc *)wmt_evt;