Bluetooth: hci_core: fix init for HCI_USER_CHANNEL

[ Upstream commit eb8c101e28496888a0dcfe16ab86a1bee369e820 ]

During the setup() stage, HCI device drivers expect the chip to
acknowledge its setup() completion via vendor specific frames.

If userspace opens() such HCI device in HCI_USER_CHANNEL [1] mode,
the vendor specific frames are never tranmitted to the driver, as
they are filtered in hci_rx_work().

Allow HCI devices which operate in HCI_USER_CHANNEL mode to receive
frames if the HCI device is is HCI_INIT state.

[1] https://www.spinics.net/lists/linux-bluetooth/msg37345.html

Fixes: 23500189 ("Bluetooth: Introduce new HCI socket channel for user operation")
Signed-off-by: NMattijs Korpershoek <mkorpershoek@baylibre.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

net/bluetooth/hci_core.c

@@ -4330,7 +4330,14 @@ static void hci_rx_work(struct work_struct *work)
 			hci_send_to_sock(hdev, skb);
 		}
 
-		if (hci_dev_test_flag(hdev, HCI_USER_CHANNEL)) {
+		/* If the device has been opened in HCI_USER_CHANNEL,
+		 * the userspace has exclusive access to device.
+		 * When device is HCI_INIT, we still need to process
+		 * the data packets to the driver in order
+		 * to complete its setup().
+		 */
+		if (hci_dev_test_flag(hdev, HCI_USER_CHANNEL) &&
+		    !test_bit(HCI_INIT, &hdev->flags)) {
 			kfree_skb(skb);
 			continue;
 		}