[PATCH] Bluetooth: mgmt: Translate HCI reason in Device Disconnected event

[PATCH] Bluetooth: mgmt: Translate HCI reason in Device Disconnected event

[Mikhail Gavrilov]

MGMT_EV_DEVICE_DISCONNECTED carries a reason field which is defined to
be one of MGMT_DEV_DISCONN_* (0x00..0x05). hci_disconn_complete_evt()
converts the HCI error with hci_to_mgmt_reason(), but two other paths
pass the raw HCI error straight through:

  hci_cs_disconnect()   -> cp->reason
  mgmt_connect_failed() -> status

The latter is reached whenever the adapter is powered off or suspended:
hci_disconnect_all_sync() aborts every link with
HCI_ERROR_REMOTE_POWER_OFF, hci_disconnect_sync() deliberately does not
wait for HCI_EV_DISCONN_COMPLETE for that reason, so that
hci_abort_conn_sync() finishes the connection off through
hci_conn_failed() instead.

As a result userspace sees an out of range reason:

  @ MGMT Event: Device Disconnected (0x000c) plen 8
        BR/EDR Address: 8C:A9:6F:2C:51:46
        Reason: Reserved (0x15)

  bluetoothd: btd_bearer_disconnected() Unknown disconnection value: 21
  bluetoothd: device_disconnected() Unknown disconnection value: 21

Export hci_to_mgmt_reason() and use it in both places, so that a power
off is reported as MGMT_DEV_DISCONN_REMOTE rather than as the raw
HCI_ERROR_REMOTE_POWER_OFF (0x15).

Fixes: d47da6bd4cfa ("Bluetooth: hci_core: Fix sending MGMT_EV_CONNECT_FAILED")
Fixes: 182ee45da083 ("Bluetooth: hci_sync: Rework hci_suspend_notifier")
Signed-off-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
---

Tested on 7.2.0-rc2 with an MT7922 controller and Denon PerL Pro
earbuds. Before the patch "systemctl stop bluetooth" produced

  @ MGMT Event: Device Disconnected  Reason: Reserved (0x15)
  bluetoothd: btd_bearer_disconnected() Unknown disconnection value: 21

and with it the event carries MGMT_DEV_DISCONN_REMOTE, with no
complaint from bluetoothd. Explicit disconnects, which take the
hci_disconn_complete_evt() path, are unchanged.

Note that the hci_cs_disconnect() call site is not reachable in
practice: it requires either hdev->suspended, in which case
mgmt_device_disconnected() overrides the reason with
MGMT_DEV_DISCONN_LOCAL_HOST_SUSPEND anyway, or a
HCI_ERROR_UNKNOWN_CONN_ID race. It is fixed for consistency only and
was not exercised by the above.

 include/net/bluetooth/hci_core.h |  1 +
 net/bluetooth/hci_event.c        | 18 +-----------------
 net/bluetooth/mgmt.c             | 19 ++++++++++++++++++-
 3 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 4ca09298e11a..e7133ff87fbf 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -2430,6 +2430,7 @@ void mgmt_new_link_key(struct hci_dev *hdev, struct link_key *key,
 		       bool persistent);
 void mgmt_device_connected(struct hci_dev *hdev, struct hci_conn *conn,
 			   u8 *name, u8 name_len);
+u8 hci_to_mgmt_reason(u8 err);
 void mgmt_device_disconnected(struct hci_dev *hdev, bdaddr_t *bdaddr,
 			      u8 link_type, u8 addr_type, u8 reason,
 			      bool mgmt_connected);
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index b6d963ce26d0..741d658e9630 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -2763,7 +2763,7 @@ static void hci_cs_disconnect(struct hci_dev *hdev, u8 status)
 	}
 
 	mgmt_device_disconnected(hdev, &conn->dst, conn->type, conn->dst_type,
-				 cp->reason, mgmt_conn);
+				 hci_to_mgmt_reason(cp->reason), mgmt_conn);
 
 	hci_disconn_cfm(conn, cp->reason);
 
@@ -3381,22 +3381,6 @@ static void hci_conn_request_evt(struct hci_dev *hdev, void *data,
 	hci_dev_unlock(hdev);
 }
 
-static u8 hci_to_mgmt_reason(u8 err)
-{
-	switch (err) {
-	case HCI_ERROR_CONNECTION_TIMEOUT:
-		return MGMT_DEV_DISCONN_TIMEOUT;
-	case HCI_ERROR_REMOTE_USER_TERM:
-	case HCI_ERROR_REMOTE_LOW_RESOURCES:
-	case HCI_ERROR_REMOTE_POWER_OFF:
-		return MGMT_DEV_DISCONN_REMOTE;
-	case HCI_ERROR_LOCAL_HOST_TERM:
-		return MGMT_DEV_DISCONN_LOCAL_HOST;
-	default:
-		return MGMT_DEV_DISCONN_UNKNOWN;
-	}
-}
-
 static void hci_disconn_complete_evt(struct hci_dev *hdev, void *data,
 				     struct sk_buff *skb)
 {
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 733a4b70e10c..1c1b64e651dc 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -9848,6 +9848,22 @@ bool mgmt_powering_down(struct hci_dev *hdev)
 	return false;
 }
 
+u8 hci_to_mgmt_reason(u8 err)
+{
+	switch (err) {
+	case HCI_ERROR_CONNECTION_TIMEOUT:
+		return MGMT_DEV_DISCONN_TIMEOUT;
+	case HCI_ERROR_REMOTE_USER_TERM:
+	case HCI_ERROR_REMOTE_LOW_RESOURCES:
+	case HCI_ERROR_REMOTE_POWER_OFF:
+		return MGMT_DEV_DISCONN_REMOTE;
+	case HCI_ERROR_LOCAL_HOST_TERM:
+		return MGMT_DEV_DISCONN_LOCAL_HOST;
+	default:
+		return MGMT_DEV_DISCONN_UNKNOWN;
+	}
+}
+
 void mgmt_device_disconnected(struct hci_dev *hdev, bdaddr_t *bdaddr,
 			      u8 link_type, u8 addr_type, u8 reason,
 			      bool mgmt_connected)
@@ -9909,7 +9925,8 @@ void mgmt_connect_failed(struct hci_dev *hdev, struct hci_conn *conn, u8 status)
 
 	if (test_and_clear_bit(HCI_CONN_MGMT_CONNECTED, &conn->flags)) {
 		mgmt_device_disconnected(hdev, &conn->dst, conn->type,
-					 conn->dst_type, status, true);
+					 conn->dst_type,
+					 hci_to_mgmt_reason(status), true);
 		return;
 	}
 
-- 
2.55.0

RE: Bluetooth: mgmt: Translate HCI reason in Device Disconnected event

[bluez.test.bot]

[-- Attachment #1: Type: text/plain, Size: 2389 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=1125289

---Test result---

Test Summary:
CheckPatch                    PASS      1.06 seconds
VerifyFixes                   PASS      0.10 seconds
VerifySignedoff               PASS      0.09 seconds
GitLint                       PASS      0.25 seconds
SubjectPrefix                 PASS      0.08 seconds
BuildKernel                   PASS      26.91 seconds
CheckAllWarning               PASS      29.67 seconds
CheckSparse                   PASS      28.29 seconds
BuildKernel32                 PASS      26.59 seconds
CheckKernelLLVM               SKIP      0.00 seconds
TestRunnerSetup               PASS      498.82 seconds
TestRunner_l2cap-tester       PASS      58.33 seconds
TestRunner_iso-tester         PASS      90.75 seconds
TestRunner_bnep-tester        PASS      18.81 seconds
TestRunner_mgmt-tester        FAIL      209.21 seconds
TestRunner_rfcomm-tester      PASS      25.35 seconds
TestRunner_sco-tester         PASS      32.72 seconds
TestRunner_ioctl-tester       PASS      25.73 seconds
TestRunner_mesh-tester        FAIL      26.28 seconds
TestRunner_smp-tester         PASS      23.59 seconds
TestRunner_userchan-tester    PASS      20.22 seconds
TestRunner_6lowpan-tester     PASS      22.22 seconds
IncrementalBuild              PASS      25.22 seconds

Details
##############################
Test: CheckKernelLLVM - SKIP
Desc: Build kernel with LLVM + context analysis
Output:
Clang not found
##############################
Test: TestRunner_mgmt-tester - FAIL
Desc: Run mgmt-tester with test-runner
Output:
Total: 494, Passed: 489 (99.0%), Failed: 1, Not Run: 4

Failed Test Cases
Read Exp Feature - Success                           Failed       0.242 seconds
##############################
Test: TestRunner_mesh-tester - FAIL
Desc: Run mesh-tester with test-runner
Output:
Total: 10, Passed: 8 (80.0%), Failed: 2, Not Run: 0

Failed Test Cases
Mesh - Send cancel - 1                               Timed out    2.662 seconds
Mesh - Send cancel - 2                               Timed out    1.990 seconds


https://github.com/bluez/bluetooth-next/pull/421

---
Regards,
Linux Bluetooth

Re: [PATCH] Bluetooth: mgmt: Translate HCI reason in Device Disconnected event

[patchwork-bot+bluetooth]

Hello:

This patch was applied to bluetooth/bluetooth-next.git (master)
by Luiz Augusto von Dentz <luiz.von.dentz@intel.com>:

On Fri, 10 Jul 2026 14:47:31 +0500 you wrote:
> MGMT_EV_DEVICE_DISCONNECTED carries a reason field which is defined to
> be one of MGMT_DEV_DISCONN_* (0x00..0x05). hci_disconn_complete_evt()
> converts the HCI error with hci_to_mgmt_reason(), but two other paths
> pass the raw HCI error straight through:
> 
>   hci_cs_disconnect()   -> cp->reason
>   mgmt_connect_failed() -> status
> 
> [...]

Here is the summary with links:
  - Bluetooth: mgmt: Translate HCI reason in Device Disconnected event
    https://git.kernel.org/bluetooth/bluetooth-next/c/eab19cb7618e

You are awesome, thank you!
-- 
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