[PATCH] Bluetooth: btusb: limit RTL8761B BROKEN_EXT_SCAN quirk to 0bda:a728

[Junjie Cao <junjie.cao@intel.com>]

Commit 5ead2063611a ("Bluetooth: btrtl: fix RTL8761B/BU broken LE
extended scan") set HCI_QUIRK_BROKEN_EXT_SCAN for every CHIP_ID_8761B
device to cure repeated 0x2042 failures on an 0bda:a728 dongle. The
brokenness is per-dongle, not per-chip: on a TP-Link UB500 (2357:0604,
RTL8761BU, fw 0xdfc6d922) extended scan works, and the legacy scan
path the quirk forces is what is broken -- LE Set Scan Enable (0x200c)
times out with -110 about 30 s after firmware load, btusb resets the
device, and the adapter re-enumerates in an endless loop (382 firmware
reloads in one boot). 7.1.8, which predates the stable backport, runs
clean on this unit; 7.1.9 loops.

Move the quirk from btrtl's chip-wide switch to a btusb device-table
flag on the USB id the original fix was verified against. Other 8761B
dongles return to their earlier long-standing behaviour.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=2521504
Fixes: 5ead2063611a ("Bluetooth: btrtl: fix RTL8761B/BU broken LE extended scan")
Cc: stable@vger.kernel.org
Signed-off-by: Junjie Cao <junjie.cao@intel.com>
---
#regzbot introduced: 5ead2063611a
#regzbot link: https://bugzilla.redhat.com/show_bug.cgi?id=2521504

 drivers/bluetooth/btrtl.c | 13 -------------
 drivers/bluetooth/btusb.c |  8 ++++++++
 2 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/drivers/bluetooth/btrtl.c b/drivers/bluetooth/btrtl.c
index 7f54d2d2d13a..03fa9409e3ee 100644
--- a/drivers/bluetooth/btrtl.c
+++ b/drivers/bluetooth/btrtl.c
@@ -1343,19 +1343,6 @@ void btrtl_set_quirks(struct hci_dev *hdev, struct btrtl_device_info *btrtl_dev)
 	if (!btrtl_dev->ic_info)
 		return;
 
-	switch (btrtl_dev->project_id) {
-	case CHIP_ID_8761B:
-		/* RTL8761B/BU reports HCI version 5.1 but does not support
-		 * the LE Extended Scan commands (Opcode 0x2042), causing
-		 * repeated -EBUSY failures when BlueZ attempts extended
-		 * scanning while a connection is active.
-		 */
-		hci_set_quirk(hdev, HCI_QUIRK_BROKEN_EXT_SCAN);
-		break;
-	default:
-		break;
-	}
-
 	switch (btrtl_dev->ic_info->lmp_subver) {
 	case RTL_ROM_LMP_8703B:
 		/* 8723CS reports two pages for local ext features,
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 2bae85b0016c..84614e60d142 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -67,6 +67,7 @@ static struct usb_driver btusb_driver;
 #define BTUSB_INTEL_NO_WBS_SUPPORT	BIT(26)
 #define BTUSB_ACTIONS_SEMI		BIT(27)
 #define BTUSB_BARROT			BIT(28)
+#define BTUSB_BROKEN_EXT_SCAN		BIT(29)
 
 static const struct usb_device_id btusb_table[] = {
 	/* Generic Bluetooth USB device */
@@ -619,6 +620,10 @@ static const struct usb_device_id quirks_table[] = {
 	{ USB_DEVICE(0x0489, 0xe130), .driver_info = BTUSB_REALTEK |
 						     BTUSB_WIDEBAND_SPEECH },
 
+	/* Realtek 8761BU Bluetooth devices */
+	{ USB_DEVICE(0x0bda, 0xa728), .driver_info = BTUSB_REALTEK |
+						     BTUSB_BROKEN_EXT_SCAN },
+
 	/* Realtek Bluetooth devices */
 	{ USB_VENDOR_AND_INTERFACE_INFO(0x0bda, 0xe0, 0x01, 0x01),
 	  .driver_info = BTUSB_REALTEK },
@@ -4403,6 +4408,9 @@ static int btusb_probe(struct usb_interface *intf,
 	if (id->driver_info & BTUSB_INVALID_LE_STATES)
 		hci_set_quirk(hdev, HCI_QUIRK_BROKEN_LE_STATES);
 
+	if (id->driver_info & BTUSB_BROKEN_EXT_SCAN)
+		hci_set_quirk(hdev, HCI_QUIRK_BROKEN_EXT_SCAN);
+
 	if (id->driver_info & BTUSB_DIGIANSWER) {
 		data->cmdreq_type = USB_TYPE_VENDOR;
 		hci_set_quirk(hdev, HCI_QUIRK_RESET_ON_CLOSE);
-- 
2.43.0