[PATCH] Revert "Bluetooth: btrtl: fix RTL8761B/BU broken LE extended scan"

[PATCH] Revert "Bluetooth: btrtl: fix RTL8761B/BU broken LE extended scan"

[Kamil Serwus]

This reverts commit 5ead2063611ae56809b1b113ac44cef9547c81d7.

It sets HCI_QUIRK_BROKEN_EXT_SCAN for every CHIP_ID_8761B, which forces
the legacy LE Set Scan Enable command (0x200c). That was validated on one
dongle, USB 0bda:a728, and it breaks others sharing the chip id: on
0bda:8771 (fw 0xdfc6d922) extended scan works fine, but the firmware
stops answering the legacy scan-disable command:

  Bluetooth: hci0: command 0x200c tx timeout
  Bluetooth: hci0: Unable to disable scanning: -110
  Bluetooth: hci0: Resetting usb device.

btusb then resets the controller, it re-enumerates and every connected
BLE device is dropped, which on a machine with a Bluetooth keyboard and
trackball leaves no input at all. v7.1.x drives the same dongle, with the
same firmware, for hours without a single scan error.

This does put 0bda:a728 back to its pre-v7.2 behaviour, where extended
scan logged repeated -EBUSY messages but the controller stayed usable. A
detection-based fix is under discussion on the list, but the culprit has
already reached 7.1.9 and 6.18.45, so the regression is better undone
first.

Fixes: 5ead2063611a ("Bluetooth: btrtl: fix RTL8761B/BU broken LE extended scan")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/linux-bluetooth/20260822141115.58815-1-kserwus@gmail.com/
Signed-off-by: Kamil Serwus <kserwus@gmail.com>
---
 drivers/bluetooth/btrtl.c | 13 -------------
 1 file changed, 13 deletions(-)

diff --git a/drivers/bluetooth/btrtl.c b/drivers/bluetooth/btrtl.c
index 7f54d2d2d..03fa9409e 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,

base-commit: 8d3ae59288f1e7d58d76558a6ee96d533bc5019f
-- 
2.55.0

RE: Revert "Bluetooth: btrtl: fix RTL8761B/BU broken LE extended scan"

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 1181 bytes --]

This is automated email and please do not reply to this email!

Dear submitter,

Thank you for submitting the patches to the linux bluetooth mailing list.
This is a CI test results with your patch series:
PW Link:https://patchwork.kernel.org/project/bluetooth/list/?series=1150368

---Test result---

Test Summary:
CheckPatch                    PASS      0.66 seconds
VerifyFixes                   PASS      0.11 seconds
VerifySignedoff               PASS      0.11 seconds
GitLint                       PASS      0.29 seconds
SubjectPrefix                 PASS      0.11 seconds
BuildKernel                   PASS      25.85 seconds
CheckAllWarning               PASS      28.19 seconds
CheckSparse                   PASS      27.06 seconds
BuildKernel32                 PASS      24.87 seconds
CheckKernelLLVM               SKIP      0.00 seconds
TestRunnerSetup               PASS      458.79 seconds
IncrementalBuild              PASS      24.58 seconds

Details
##############################
Test: CheckKernelLLVM - SKIP
Desc: Build kernel with LLVM + context analysis
Output:
Clang not found


https://github.com/bluez/bluetooth-next/pull/637

---
Regards,
Linux Bluetooth

Re: [PATCH] Revert "Bluetooth: btrtl: fix RTL8761B/BU broken LE extended scan"

[Sasha Levin]

On Sun, Aug 23, 2026 at 12:29:59PM +0200, Kamil Serwus wrote:
> This reverts commit 5ead2063611ae56809b1b113ac44cef9547c81d7.
>
> It sets HCI_QUIRK_BROKEN_EXT_SCAN for every CHIP_ID_8761B, which forces
> the legacy LE Set Scan Enable command (0x200c). That was validated on one
> dongle, USB 0bda:a728, and it breaks others sharing the chip id

5ead2063611a ("Bluetooth: btrtl: fix RTL8761B/BU broken LE extended
scan") is still in mainline, so I'd rather not carry a stable-only revert
ahead of it - that would just make the stable trees diverge from Linus'.

Please get the revert (or the detection-based fix under discussion)
merged upstream. Once it is in mainline with a stable tag we will pick it
up for 7.1.y and 6.18.y the normal way.

-- 
Thanks,
Sasha