Dear Arkadiusz,
Thank you for the patch.
Am 26.08.25 um 19:03 schrieb Arkadiusz Bokowy:
Some Barrot based USB Bluetooth dongles erroneously send one extra
random byte for the HCI_OP_READ_LOCAL_EXT_FEATURES command. The
consequence of that is that the next HCI transfer is misaligned by one
byte causing undefined behavior. In most cases the response event for
the next command fails with random error code.
Since the HCI_OP_READ_LOCAL_EXT_FEATURES command is used during HCI
controller initialization, the initialization fails rendering the USB
dongle not usable.
[59.464099] usb 1-1.3: new full-speed USB device number 11 using xhci_hcd
[59.561617] usb 1-1.3: New USB device found, idVendor=33fa, idProduct=0012, bcdDevice=88.91
[59.561642] usb 1-1.3: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[59.561656] usb 1-1.3: Product: UGREEN BT6.0 Adapter
[61.720116] Bluetooth: hci1: command 0x1005 tx timeout
[61.720167] Bluetooth: hci1: Opcode 0x1005 failed: -110
This patch was tested with the 33fa:0012 device. Now the device is
initialized properly:
[43.329852] usb 1-1.4: new full-speed USB device number 4 using dwc_otg
[43.446790] usb 1-1.4: New USB device found, idVendor=33fa, idProduct=0012, bcdDevice=88.91
[43.446813] usb 1-1.4: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[43.446821] usb 1-1.4: Product: UGREEN BT6.0 Adapter
[43.582024] Bluetooth: hci1: Unexpected continuation: 1 bytes
[43.703025] Bluetooth: hci1: Unexpected continuation: 1 bytes
As a normal user reading the logs and seeing the warning, I wouldn’t
know what to do. So, I’d elaborate, that it’s probably a controller (of
the dongle) issue, and, if at all, should be reported to the hardware
vendor.
… Unexpected continuation: 1 bytes. This is likely a problem with the
Bluetooth device and should be reported to the manufacturer.
[43.750141] Bluetooth: MGMT ver 1.23
Signed-off-by: Arkadiusz Bokowy <arkadiusz.bokowy@xxxxxxxxx>
Tested-by: Arkadiusz Bokowy <arkadiusz.bokowy@xxxxxxxxx>
I believe, the author does not need to add a dedicated Tested-by: tag,
as it’s kind of expected. But I am not 100 % sure
(`Documentation/process/5.Posting.rst` does not handle the case) and
it’s not important.
---
drivers/bluetooth/btusb.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 8085fabad..24a249d1c 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -1192,6 +1192,18 @@ static int btusb_recv_intr(struct btusb_data *data, void *buffer, int count)
}
if (!hci_skb_expect(skb)) {
+ /* Each chunk should correct to at least 1 or more
+ * events so if there are still bytes left that doesn't
+ * constitute a new event this is likely a bug in the
+ * controller.
+ */
+ if (count && count < HCI_EVENT_HDR_SIZE) {
+ bt_dev_warn(data->hdev,
+ "Unexpected continuation: %d bytes",
+ count);
+ count = 0;
+ }
+
/* Complete frame */
btusb_recv_event(data, skb);
skb = NULL;
Kind regards,
Paul
