Bluetooth: Add new quirk for broken read key length on ATS2851

[ Upstream commit 48201a3 ] The ATS2851 controller erroneously reports support for the "Read Encryption Key Length" HCI command. This makes it unable to connect to any devices, since this command is issued by the kernel during the connection process in response to an "Encryption Change" HCI event. Add a new quirk (HCI_QUIRK_BROKEN_ENC_KEY_SIZE) to hint that the command is unsupported, preventing it from interrupting the connection process. This is the error log from btmon before this patch: > HCI Event: Encryption Change (0x08) plen 4 Status: Success (0x00) Handle: 2048 Address: ... Encryption: Enabled with E0 (0x01) < HCI Command: Read Encryption Key Size (0x05|0x0008) plen 2 Handle: 2048 Address: ... > HCI Event: Command Status (0x0f) plen 4 Read Encryption Key Size (0x05|0x0008) ncmd 1 Status: Unknown HCI Command (0x01) Signed-off-by: Vinicius Peixoto <[email protected]> Signed-off-by: Luiz Augusto von Dentz <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
tobetter · Apr 13, 2024 · 8677a14 · 8677a14
1 parent 6d0950c
commit 8677a14
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Showing 3 changed files with 11 additions and 1 deletion.
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
@@ -4477,6 +4477,7 @@ static int btusb_probe(struct usb_interface *intf,
 		set_bit(HCI_QUIRK_BROKEN_READ_TRANSMIT_POWER, &hdev->quirks);
 		set_bit(HCI_QUIRK_BROKEN_SET_RPA_TIMEOUT, &hdev->quirks);
 		set_bit(HCI_QUIRK_BROKEN_EXT_SCAN, &hdev->quirks);
+		set_bit(HCI_QUIRK_BROKEN_READ_ENC_KEY_SIZE, &hdev->quirks);
 	}
 
 	if (!reset)

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
@@ -339,6 +339,14 @@ enum {
 	 * during the hdev->setup vendor callback.
 	 */
 	HCI_QUIRK_BROKEN_LE_CODED,
+
+	/*
+	 * When this quirk is set, the HCI_OP_READ_ENC_KEY_SIZE command is
+	 * skipped during an HCI_EV_ENCRYPT_CHANGE event. This is required
+	 * for Actions Semiconductor ATS2851 based controllers, which erroneously
+	 * claim to support it.
+	 */
+	HCI_QUIRK_BROKEN_READ_ENC_KEY_SIZE,
 };
 
 /* HCI device flags */

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
@@ -3679,7 +3679,8 @@ static void hci_encrypt_change_evt(struct hci_dev *hdev, void *data,
 		 * controller really supports it. If it doesn't, assume
 		 * the default size (16).
 		 */
-		if (!(hdev->commands[20] & 0x10)) {
+		if (!(hdev->commands[20] & 0x10) ||
+		    test_bit(HCI_QUIRK_BROKEN_READ_ENC_KEY_SIZE, &hdev->quirks)) {
 			conn->enc_key_size = HCI_LINK_KEY_SIZE;
 			goto notify;
 		}