summaryrefslogtreecommitdiff
path: root/drivers/bluetooth
diff options
context:
space:
mode:
authorIsmael Ferreras Morezuelas <swyterzone@gmail.com>2020-07-26 23:12:28 +0200
committerMarcel Holtmann <marcel@holtmann.org>2020-07-28 09:09:00 +0200
commitcde1a8a992875a7479c4321b2a4a190c2e92ec2a (patch)
treebef64ce46e642c79be556564063b7c1858230011 /drivers/bluetooth
parent339ddaa626995bc6218972ca241471f3717cc5f4 (diff)
Bluetooth: btusb: Fix and detect most of the Chinese Bluetooth controllers
For some reason they tend to squat on the very first CSR/ Cambridge Silicon Radio VID/PID instead of paying fees. This is an extremely common problem; the issue goes as back as 2013 and these devices are only getting more popular, even rebranded by reputable vendors and sold by retailers everywhere. So, at this point in time there are hundreds of modern dongles reusing the ID of what originally was an early Bluetooth 1.1 controller. Linux is the only place where they don't work due to spotty checks in our detection code. It only covered a minimum subset. So what's the big idea? Take advantage of the fact that all CSR chips report the same internal version as both the LMP sub-version and HCI revision number. It always matches, couple that with the manufacturer code, that rarely lies, and we now have a good idea of who is who. Additionally, by compiling a list of user-reported HCI/lsusb dumps, and searching around for legit CSR dongles in similar product ranges we can find what CSR BlueCore firmware supported which Bluetooth versions. That way we can narrow down ranges of fakes for each of them. e.g. Real CSR dongles with LMP subversion 0x73 are old enough that support BT 1.1 only; so it's a dead giveaway when some third-party BT 4.0 dongle reuses it. So, to sum things up; there are multiple classes of fake controllers reusing the same 0A12:0001 VID/PID. This has been broken for a while. Known 'fake' bcdDevices: 0x0100, 0x0134, 0x1915, 0x2520, 0x7558, 0x8891 IC markings on 0x7558: FR3191AHAL 749H15143 (???) https://bugzilla.kernel.org/show_bug.cgi?id=60824 Fixes: 81cac64ba258ae (Deal with USB devices that are faking CSR vendor) Reported-by: Michał Wiśniewski <brylozketrzyn@gmail.com> Tested-by: Mike Johnson <yuyuyak@gmail.com> Tested-by: Ricardo Rodrigues <ekatonb@gmail.com> Tested-by: M.Hanny Sabbagh <mhsabbagh@outlook.com> Tested-by: Oussama BEN BRAHIM <b.brahim.oussama@gmail.com> Tested-by: Ismael Ferreras Morezuelas <swyterzone@gmail.com> Signed-off-by: Ismael Ferreras Morezuelas <swyterzone@gmail.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'drivers/bluetooth')
-rw-r--r--drivers/bluetooth/btusb.c74
1 files changed, 64 insertions, 10 deletions
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index aa0bc9942afd..1f51494f5818 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -1742,6 +1742,7 @@ static int btusb_setup_csr(struct hci_dev *hdev)
{
struct hci_rp_read_local_version *rp;
struct sk_buff *skb;
+ bool is_fake = false;
BT_DBG("%s", hdev->name);
@@ -1761,18 +1762,69 @@ static int btusb_setup_csr(struct hci_dev *hdev)
rp = (struct hci_rp_read_local_version *)skb->data;
- /* Detect controllers which aren't real CSR ones. */
+ /* Detect a wide host of Chinese controllers that aren't CSR.
+ *
+ * Known fake bcdDevices: 0x0100, 0x0134, 0x1915, 0x2520, 0x7558, 0x8891
+ *
+ * The main thing they have in common is that these are really popular low-cost
+ * options that support newer Bluetooth versions but rely on heavy VID/PID
+ * squatting of this poor old Bluetooth 1.1 device. Even sold as such.
+ *
+ * We detect actual CSR devices by checking that the HCI manufacturer code
+ * is Cambridge Silicon Radio (10) and ensuring that LMP sub-version and
+ * HCI rev values always match. As they both store the firmware number.
+ */
if (le16_to_cpu(rp->manufacturer) != 10 ||
- le16_to_cpu(rp->lmp_subver) == 0x0c5c) {
+ le16_to_cpu(rp->hci_rev) != le16_to_cpu(rp->lmp_subver))
+ is_fake = true;
+
+ /* Known legit CSR firmware build numbers and their supported BT versions:
+ * - 1.1 (0x1) -> 0x0073, 0x020d, 0x033c, 0x034e
+ * - 1.2 (0x2) -> 0x04d9, 0x0529
+ * - 2.0 (0x3) -> 0x07a6, 0x07ad, 0x0c5c
+ * - 2.1 (0x4) -> 0x149c, 0x1735, 0x1899 (0x1899 is a BlueCore4-External)
+ * - 4.0 (0x6) -> 0x1d86, 0x2031, 0x22bb
+ *
+ * e.g. Real CSR dongles with LMP subversion 0x73 are old enough that
+ * support BT 1.1 only; so it's a dead giveaway when some
+ * third-party BT 4.0 dongle reuses it.
+ */
+ else if (le16_to_cpu(rp->lmp_subver) <= 0x034e &&
+ le16_to_cpu(rp->hci_ver) > BLUETOOTH_VER_1_1)
+ is_fake = true;
+
+ else if (le16_to_cpu(rp->lmp_subver) <= 0x0529 &&
+ le16_to_cpu(rp->hci_ver) > BLUETOOTH_VER_1_2)
+ is_fake = true;
+
+ else if (le16_to_cpu(rp->lmp_subver) <= 0x0c5c &&
+ le16_to_cpu(rp->hci_ver) > BLUETOOTH_VER_2_0)
+ is_fake = true;
+
+ else if (le16_to_cpu(rp->lmp_subver) <= 0x1899 &&
+ le16_to_cpu(rp->hci_ver) > BLUETOOTH_VER_2_1)
+ is_fake = true;
+
+ else if (le16_to_cpu(rp->lmp_subver) <= 0x22bb &&
+ le16_to_cpu(rp->hci_ver) > BLUETOOTH_VER_4_0)
+ is_fake = true;
+
+ if (is_fake) {
+ bt_dev_warn(hdev, "CSR: Unbranded CSR clone detected; adding workarounds...");
+
+ /* Generally these clones have big discrepancies between
+ * advertised features and what's actually supported.
+ * Probably will need to be expanded in the future;
+ * without these the controller will lock up.
+ */
+ set_bit(HCI_QUIRK_BROKEN_STORED_LINK_KEY, &hdev->quirks);
+ set_bit(HCI_QUIRK_BROKEN_ERR_DATA_REPORTING, &hdev->quirks);
+
/* Clear the reset quirk since this is not an actual
* early Bluetooth 1.1 device from CSR.
*/
clear_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
-
- /* These fake CSR controllers have all a broken
- * stored link key handling and so just disable it.
- */
- set_bit(HCI_QUIRK_BROKEN_STORED_LINK_KEY, &hdev->quirks);
+ clear_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks);
}
kfree_skb(skb);
@@ -4070,11 +4122,13 @@ static int btusb_probe(struct usb_interface *intf,
if (bcdDevice < 0x117)
set_bit(HCI_QUIRK_RESET_ON_CLOSE, &hdev->quirks);
+ /* This must be set first in case we disable it for fakes */
+ set_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks);
+
/* Fake CSR devices with broken commands */
- if (bcdDevice <= 0x100 || bcdDevice == 0x134)
+ if (le16_to_cpu(udev->descriptor.idVendor) == 0x0a12 &&
+ le16_to_cpu(udev->descriptor.idProduct) == 0x0001)
hdev->setup = btusb_setup_csr;
-
- set_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks);
}
if (id->driver_info & BTUSB_SNIFFER) {