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

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 <nukelet64@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index b09fe480e708f95d6470fde6dbca617faf5bfbcb..06e915b57283f8ca3d3ab19b64e1e248e6ecb2bc 100644 (file)
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -4500,6 +4500,7 @@ 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
index 21099bd3c8bcee685d51df32be17834da499121c..8701ca5f31eec353bb793ac44acef21445337cdf 100644 (file)
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -330,6 +330,14 @@ 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
index bffd2c7ff6087b3e250e2446956b0d5f3f91fd33..4ae2248240121c6c36040b2af182c1bcd3b19944 100644 (file)
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3641,7 +3641,8 @@ 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;
                }