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Subject[PATCH v4 2/2] Bluetooth: btusb: Use quirk to skip HCI_FLT_CLEAR_ALL on fake CSR controllers
Another subset of the more recent batch of Chinese clones aren't
specs-compliant and seem to lock up whenever they receive a
HCI_OP_SET_EVENT_FLT with flt_type set to zero/HCI_FLT_CLEAR_ALL,
which on Linux (until the recent HCI state-machine refactor) happened
right at BR/EDR setup. As there are other less-straightforward ways
of reaching those operations, this patch is still relevant.

So, while all the previous efforts to wrangle the herd of fake CSRs
seem to be paying off (and these also get detected as such) we
still need to take care of this quirk; testers seem to agree
that these dongles tend to work well enough afterwards.

From some cursory USB packet capture on Windows it seems like
that driver doesn't appear to use this clear-all functionality at all.

This patch was tested on some really popular AliExpress-style
dongles, in my case marked as "V5.0". Chip markings: UG8413,
the backside of the PCB says "USB Dangel" (sic).

Here is the `hciconfig -a` output; for completeness:

hci0: Type: Primary Bus: USB
BD Address: 00:1A:7D:DA:7X:XX ACL MTU: 679:8 SCO MTU: 48:16
Features: 0xbf 0x3e 0x4d 0xfa 0xdb 0x3d 0x7b 0xc7
Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3
Link policy: RSWITCH SNIFF
Name: 'CSR8510 A10.'
Class: 0x7c0104
Service Classes: Rendering, Capturing, Object Transfer, Audio, Telephony
Device Class: Computer, Desktop workstation
HCI Version: 4.0 (0x6) Revision: 0x3120
LMP Version: 4.0 (0x6) Subversion: 0x22bb
Manufacturer: Cambridge Silicon Radio (10)

As well as the `lsusb -vv -d 0a12:0001`:

ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 224 Wireless
bDeviceSubClass 1 Radio Frequency
bDeviceProtocol 1 Bluetooth
bMaxPacketSize0 64
idVendor 0x0a12 Cambridge Silicon Radio, Ltd
idProduct 0x0001 Bluetooth Dongle (HCI mode)
bcdDevice 88.91
iManufacturer 0
iProduct 2 BT DONGLE10
iSerial 0
bNumConfigurations 1

Also, changed the benign dmesg print that shows up whenever the
generic force-suspend fails from bt_dev_err to bt_dev_warn;
it's okay and done on a best-effort basis, not a problem
if that does not work.

Also, swapped the HCI subver and LMP subver numbers for the Barrot
in the comment, which I copied wrong the last time around.

Fixes: 81cac64ba258a ("Bluetooth: Deal with USB devices that are faking CSR vendor")
Fixes: cde1a8a992875 ("Bluetooth: btusb: Fix and detect most of the Chinese Bluetooth controllers")
Fixes: d74e0ae7e0303 ("Bluetooth: btusb: Fix detection of some fake CSR controllers with a bcdDevice val of 0x0134")
Fixes: 0671c0662383e ("Bluetooth: btusb: Add workaround for remote-wakeup issues with Barrot 8041a02 fake CSR controllers")
Fixes: f4292e2faf522 ("Bluetooth: btusb: Make the CSR clone chip force-suspend workaround more generic")


Cc: Hans de Goede <>
Tested-by: Gonzalo Tornaría <>
Tested-by: Mateus Lemos <>
Tested-by: Ismael Ferreras Morezuelas <>
Signed-off-by: Ismael Ferreras Morezuelas <>
drivers/bluetooth/btusb.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 1bb00b7547fb..73a4c9dd77c2 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -2057,6 +2057,8 @@ static int btusb_setup_csr(struct hci_dev *hdev)
set_bit(HCI_QUIRK_BROKEN_STORED_LINK_KEY, &hdev->quirks);
set_bit(HCI_QUIRK_BROKEN_ERR_DATA_REPORTING, &hdev->quirks);
+ set_bit(HCI_QUIRK_BROKEN_FILTER_CLEAR_ALL, &hdev->quirks);
+ set_bit(HCI_QUIRK_NO_SUSPEND_NOTIFIER, &hdev->quirks);

/* Clear the reset quirk since this is not an actual
* early Bluetooth 1.1 device from CSR.
@@ -2067,7 +2069,7 @@ static int btusb_setup_csr(struct hci_dev *hdev)
* Special workaround for these BT 4.0 chip clones, and potentially more:
- * - 0x0134: a Barrot 8041a02 (HCI rev: 0x1012 sub: 0x0810)
+ * - 0x0134: a Barrot 8041a02 (HCI rev: 0x0810 sub: 0x1012)
* - 0x7558: IC markings FR3191AHAL 749H15143 (HCI rev/sub-version: 0x0709)
* These controllers are really messed-up.
@@ -2096,7 +2098,7 @@ static int btusb_setup_csr(struct hci_dev *hdev)
if (ret >= 0)
- bt_dev_err(hdev, "CSR: Failed to suspend the device for our Barrot 8041a02 receive-issue workaround");
+ bt_dev_warn(hdev, "CSR: Couldn't suspend the device for our Barrot 8041a02 receive-issue workaround");


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