[PATCH v2] Bluetooth: hci_event: Add support for handling LE BIG Sync Lost event

[PATCH v2] Bluetooth: hci_event: Add support for handling LE BIG Sync Lost event

[Yang Li via B4 Relay]

From: Yang Li <yang.li@amlogic.com>

When the BIS source stops, the controller sends an LE BIG Sync Lost
event (subevent 0x1E). Currently, this event is not handled, causing
the BIS stream to remain active in BlueZ and preventing recovery.

Signed-off-by: Yang Li <yang.li@amlogic.com>
---
Changes in v2:
- Matching the BIG handle is required when looking up a BIG connection.
- Use ev->reason to determine the cause of disconnection.
- Call hci_conn_del after hci_disconnect_cfm to remove the connection entry
- Delete the big connection
- Link to v1: https://lore.kernel.org/r/20250624-handle_big_sync_lost_event-v1-1-c32ce37dd6a5@amlogic.com
---
 include/net/bluetooth/hci.h |  6 ++++++
 net/bluetooth/hci_event.c   | 31 +++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 82cbd54443ac..48389a64accb 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -2849,6 +2849,12 @@ struct hci_evt_le_big_sync_estabilished {
 	__le16  bis[];
 } __packed;
 
+#define HCI_EVT_LE_BIG_SYNC_LOST 0x1e
+struct hci_evt_le_big_sync_lost {
+	__u8    handle;
+	__u8    reason;
+} __packed;
+
 #define HCI_EVT_LE_BIG_INFO_ADV_REPORT	0x22
 struct hci_evt_le_big_info_adv_report {
 	__le16  sync_handle;
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 66052d6aaa1d..d0b9c8dca891 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -7026,6 +7026,32 @@ static void hci_le_big_sync_established_evt(struct hci_dev *hdev, void *data,
 	hci_dev_unlock(hdev);
 }
 
+static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
+					    struct sk_buff *skb)
+{
+	struct hci_evt_le_big_sync_lost *ev = data;
+	struct hci_conn *bis, *conn;
+
+	bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
+
+	hci_dev_lock(hdev);
+
+	list_for_each_entry(bis, &hdev->conn_hash.list, list) {
+		if (test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags) &&
+		    (bis->iso_qos.bcast.big == ev->handle)) {
+			hci_disconn_cfm(bis, ev->reason);
+			hci_conn_del(bis);
+
+			/* Delete the big connection */
+			conn = hci_conn_hash_lookup_pa_sync_handle(hdev, bis->sync_handle);
+			if (conn)
+				hci_conn_del(conn);
+		}
+	}
+
+	hci_dev_unlock(hdev);
+}
+
 static void hci_le_big_info_adv_report_evt(struct hci_dev *hdev, void *data,
 					   struct sk_buff *skb)
 {
@@ -7149,6 +7175,11 @@ static const struct hci_le_ev {
 		     hci_le_big_sync_established_evt,
 		     sizeof(struct hci_evt_le_big_sync_estabilished),
 		     HCI_MAX_EVENT_SIZE),
+	/* [0x1e = HCI_EVT_LE_BIG_SYNC_LOST] */
+	HCI_LE_EV_VL(HCI_EVT_LE_BIG_SYNC_LOST,
+		     hci_le_big_sync_lost_evt,
+		     sizeof(struct hci_evt_le_big_sync_lost),
+		     HCI_MAX_EVENT_SIZE),
 	/* [0x22 = HCI_EVT_LE_BIG_INFO_ADV_REPORT] */
 	HCI_LE_EV_VL(HCI_EVT_LE_BIG_INFO_ADV_REPORT,
 		     hci_le_big_info_adv_report_evt,

---
base-commit: bd35cd12d915bc410c721ba28afcada16f0ebd16
change-id: 20250612-handle_big_sync_lost_event-4c7dc64390a2

Best regards,
-- 
Yang Li <yang.li@amlogic.com>

RE: [v2] Bluetooth: hci_event: Add support for handling LE BIG Sync Lost event

[bluez.test.bot]

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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=975638

---Test result---

Test Summary:
CheckPatch                    PENDING   0.27 seconds
GitLint                       PENDING   0.25 seconds
SubjectPrefix                 PASS      0.09 seconds
BuildKernel                   PASS      25.26 seconds
CheckAllWarning               PASS      27.56 seconds
CheckSparse                   WARNING   31.23 seconds
BuildKernel32                 PASS      24.98 seconds
TestRunnerSetup               PASS      483.50 seconds
TestRunner_l2cap-tester       PASS      25.59 seconds
TestRunner_iso-tester         PASS      36.46 seconds
TestRunner_bnep-tester        PASS      6.13 seconds
TestRunner_mgmt-tester        PASS      133.91 seconds
TestRunner_rfcomm-tester      PASS      9.47 seconds
TestRunner_sco-tester         PASS      14.92 seconds
TestRunner_ioctl-tester       PASS      10.07 seconds
TestRunner_mesh-tester        PASS      7.50 seconds
TestRunner_smp-tester         PASS      8.65 seconds
TestRunner_userchan-tester    PASS      6.18 seconds
IncrementalBuild              PENDING   0.82 seconds

Details
##############################
Test: CheckPatch - PENDING
Desc: Run checkpatch.pl script
Output:

##############################
Test: GitLint - PENDING
Desc: Run gitlint
Output:

##############################
Test: CheckSparse - WARNING
Desc: Run sparse tool with linux kernel
Output:
net/bluetooth/hci_event.c: note: in included file (through include/net/bluetooth/hci_core.h):
##############################
Test: IncrementalBuild - PENDING
Desc: Incremental build with the patches in the series
Output:



---
Regards,
Linux Bluetooth

Re: [PATCH v2] Bluetooth: hci_event: Add support for handling LE BIG Sync Lost event

[Pauli Virtanen]

Hi,

ke, 2025-06-25 kello 16:42 +0800, Yang Li via B4 Relay kirjoitti:
> From: Yang Li <yang.li@amlogic.com>
> 
> When the BIS source stops, the controller sends an LE BIG Sync Lost
> event (subevent 0x1E). Currently, this event is not handled, causing
> the BIS stream to remain active in BlueZ and preventing recovery.
> 
> Signed-off-by: Yang Li <yang.li@amlogic.com>
> ---
> Changes in v2:
> - Matching the BIG handle is required when looking up a BIG connection.
> - Use ev->reason to determine the cause of disconnection.
> - Call hci_conn_del after hci_disconnect_cfm to remove the connection entry
> - Delete the big connection
> - Link to v1: https://lore.kernel.org/r/20250624-handle_big_sync_lost_event-v1-1-c32ce37dd6a5@amlogic.com
> ---
>  include/net/bluetooth/hci.h |  6 ++++++
>  net/bluetooth/hci_event.c   | 31 +++++++++++++++++++++++++++++++
>  2 files changed, 37 insertions(+)
> 
> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> index 82cbd54443ac..48389a64accb 100644
> --- a/include/net/bluetooth/hci.h
> +++ b/include/net/bluetooth/hci.h
> @@ -2849,6 +2849,12 @@ struct hci_evt_le_big_sync_estabilished {
>  	__le16  bis[];
>  } __packed;
>  
> +#define HCI_EVT_LE_BIG_SYNC_LOST 0x1e
> +struct hci_evt_le_big_sync_lost {
> +	__u8    handle;
> +	__u8    reason;
> +} __packed;
> +
>  #define HCI_EVT_LE_BIG_INFO_ADV_REPORT	0x22
>  struct hci_evt_le_big_info_adv_report {
>  	__le16  sync_handle;
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index 66052d6aaa1d..d0b9c8dca891 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -7026,6 +7026,32 @@ static void hci_le_big_sync_established_evt(struct hci_dev *hdev, void *data,
>  	hci_dev_unlock(hdev);
>  }
>  
> +static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
> +					    struct sk_buff *skb)
> +{
> +	struct hci_evt_le_big_sync_lost *ev = data;
> +	struct hci_conn *bis, *conn;
> +
> +	bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
> +
> +	hci_dev_lock(hdev);
> +
> +	list_for_each_entry(bis, &hdev->conn_hash.list, list) {

This should check bis->type == BIS_LINK too.

> +		if (test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags) &&
> +		    (bis->iso_qos.bcast.big == ev->handle)) {
> +			hci_disconn_cfm(bis, ev->reason);
> +			hci_conn_del(bis);
> +
> +			/* Delete the big connection */
> +			conn = hci_conn_hash_lookup_pa_sync_handle(hdev, bis->sync_handle);
> +			if (conn)
> +				hci_conn_del(conn);

Problems:

- use after free

- hci_conn_del() cannot be used inside list_for_each_entry() 
  of the connection list

- also list_for_each_entry_safe() allows deleting only the iteration
  cursor, so some restructuring above is needed


> +		}
> +	}
> +
> +	hci_dev_unlock(hdev);
> +}
> +
>  static void hci_le_big_info_adv_report_evt(struct hci_dev *hdev, void *data,
>  					   struct sk_buff *skb)
>  {
> @@ -7149,6 +7175,11 @@ static const struct hci_le_ev {
>  		     hci_le_big_sync_established_evt,
>  		     sizeof(struct hci_evt_le_big_sync_estabilished),
>  		     HCI_MAX_EVENT_SIZE),
> +	/* [0x1e = HCI_EVT_LE_BIG_SYNC_LOST] */
> +	HCI_LE_EV_VL(HCI_EVT_LE_BIG_SYNC_LOST,
> +		     hci_le_big_sync_lost_evt,
> +		     sizeof(struct hci_evt_le_big_sync_lost),
> +		     HCI_MAX_EVENT_SIZE),
>  	/* [0x22 = HCI_EVT_LE_BIG_INFO_ADV_REPORT] */
>  	HCI_LE_EV_VL(HCI_EVT_LE_BIG_INFO_ADV_REPORT,
>  		     hci_le_big_info_adv_report_evt,
> 
> ---
> base-commit: bd35cd12d915bc410c721ba28afcada16f0ebd16
> change-id: 20250612-handle_big_sync_lost_event-4c7dc64390a2
> 
> Best regards,

-- 
Pauli Virtanen

Re: [PATCH v2] Bluetooth: hci_event: Add support for handling LE BIG Sync Lost event

[Yang Li]

Hi Pauli,
> [ EXTERNAL EMAIL ]
>
> Hi,
>
> ke, 2025-06-25 kello 16:42 +0800, Yang Li via B4 Relay kirjoitti:
>> From: Yang Li <yang.li@amlogic.com>
>>
>> When the BIS source stops, the controller sends an LE BIG Sync Lost
>> event (subevent 0x1E). Currently, this event is not handled, causing
>> the BIS stream to remain active in BlueZ and preventing recovery.
>>
>> Signed-off-by: Yang Li <yang.li@amlogic.com>
>> ---
>> Changes in v2:
>> - Matching the BIG handle is required when looking up a BIG connection.
>> - Use ev->reason to determine the cause of disconnection.
>> - Call hci_conn_del after hci_disconnect_cfm to remove the connection entry
>> - Delete the big connection
>> - Link to v1: https://lore.kernel.org/r/20250624-handle_big_sync_lost_event-v1-1-c32ce37dd6a5@amlogic.com
>> ---
>>   include/net/bluetooth/hci.h |  6 ++++++
>>   net/bluetooth/hci_event.c   | 31 +++++++++++++++++++++++++++++++
>>   2 files changed, 37 insertions(+)
>>
>> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
>> index 82cbd54443ac..48389a64accb 100644
>> --- a/include/net/bluetooth/hci.h
>> +++ b/include/net/bluetooth/hci.h
>> @@ -2849,6 +2849,12 @@ struct hci_evt_le_big_sync_estabilished {
>>        __le16  bis[];
>>   } __packed;
>>
>> +#define HCI_EVT_LE_BIG_SYNC_LOST 0x1e
>> +struct hci_evt_le_big_sync_lost {
>> +     __u8    handle;
>> +     __u8    reason;
>> +} __packed;
>> +
>>   #define HCI_EVT_LE_BIG_INFO_ADV_REPORT       0x22
>>   struct hci_evt_le_big_info_adv_report {
>>        __le16  sync_handle;
>> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
>> index 66052d6aaa1d..d0b9c8dca891 100644
>> --- a/net/bluetooth/hci_event.c
>> +++ b/net/bluetooth/hci_event.c
>> @@ -7026,6 +7026,32 @@ static void hci_le_big_sync_established_evt(struct hci_dev *hdev, void *data,
>>        hci_dev_unlock(hdev);
>>   }
>>
>> +static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
>> +                                         struct sk_buff *skb)
>> +{
>> +     struct hci_evt_le_big_sync_lost *ev = data;
>> +     struct hci_conn *bis, *conn;
>> +
>> +     bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
>> +
>> +     hci_dev_lock(hdev);
>> +
>> +     list_for_each_entry(bis, &hdev->conn_hash.list, list) {
> This should check bis->type == BIS_LINK too.
Will do.
>
>> +             if (test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags) &&
>> +                 (bis->iso_qos.bcast.big == ev->handle)) {
>> +                     hci_disconn_cfm(bis, ev->reason);
>> +                     hci_conn_del(bis);
>> +
>> +                     /* Delete the big connection */
>> +                     conn = hci_conn_hash_lookup_pa_sync_handle(hdev, bis->sync_handle);
>> +                     if (conn)
>> +                             hci_conn_del(conn);
> Problems:
>
> - use after free
>
> - hci_conn_del() cannot be used inside list_for_each_entry()
>    of the connection list
>
> - also list_for_each_entry_safe() allows deleting only the iteration
>    cursor, so some restructuring above is needed

Following your suggestion, I updated the hci_le_big_sync_lost_evt function.

+static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
+                                           struct sk_buff *skb)
+{
+       struct hci_evt_le_big_sync_lost *ev = data;
+       struct hci_conn *bis, *conn, *n;
+
+       bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
+
+       hci_dev_lock(hdev);
+
+       /* Delete the pa sync connection */
+       bis = hci_conn_hash_lookup_pa_sync_big_handle(hdev, ev->handle);
+       if (bis) {
+               conn = hci_conn_hash_lookup_pa_sync_handle(hdev, 
bis->sync_handle);
+               if (conn)
+                       hci_conn_del(conn);
+       }
+
+       /* Delete each bis connection */
+       list_for_each_entry_safe(bis, n, &hdev->conn_hash.list, list) {
+               if (bis->type == BIS_LINK &&
+                   bis->iso_qos.bcast.big == ev->handle &&
+                   test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags)) {
+                       hci_disconn_cfm(bis, ev->reason);
+                       hci_conn_del(bis);
+               }
+       }
+
+       hci_dev_unlock(hdev);
+}

>
>> +             }
>> +     }
>> +
>> +     hci_dev_unlock(hdev);
>> +}
>> +
>>   static void hci_le_big_info_adv_report_evt(struct hci_dev *hdev, void *data,
>>                                           struct sk_buff *skb)
>>   {
>> @@ -7149,6 +7175,11 @@ static const struct hci_le_ev {
>>                     hci_le_big_sync_established_evt,
>>                     sizeof(struct hci_evt_le_big_sync_estabilished),
>>                     HCI_MAX_EVENT_SIZE),
>> +     /* [0x1e = HCI_EVT_LE_BIG_SYNC_LOST] */
>> +     HCI_LE_EV_VL(HCI_EVT_LE_BIG_SYNC_LOST,
>> +                  hci_le_big_sync_lost_evt,
>> +                  sizeof(struct hci_evt_le_big_sync_lost),
>> +                  HCI_MAX_EVENT_SIZE),
>>        /* [0x22 = HCI_EVT_LE_BIG_INFO_ADV_REPORT] */
>>        HCI_LE_EV_VL(HCI_EVT_LE_BIG_INFO_ADV_REPORT,
>>                     hci_le_big_info_adv_report_evt,
>>
>> ---
>> base-commit: bd35cd12d915bc410c721ba28afcada16f0ebd16
>> change-id: 20250612-handle_big_sync_lost_event-4c7dc64390a2
>>
>> Best regards,
> --
> Pauli Virtanen

Re: [PATCH v2] Bluetooth: hci_event: Add support for handling LE BIG Sync Lost event

[Luiz Augusto von Dentz]

Hi Yang,

On Thu, Jun 26, 2025 at 1:54 AM Yang Li <yang.li@amlogic.com> wrote:
>
> Hi Pauli,
> > [ EXTERNAL EMAIL ]
> >
> > Hi,
> >
> > ke, 2025-06-25 kello 16:42 +0800, Yang Li via B4 Relay kirjoitti:
> >> From: Yang Li <yang.li@amlogic.com>
> >>
> >> When the BIS source stops, the controller sends an LE BIG Sync Lost
> >> event (subevent 0x1E). Currently, this event is not handled, causing
> >> the BIS stream to remain active in BlueZ and preventing recovery.
> >>
> >> Signed-off-by: Yang Li <yang.li@amlogic.com>
> >> ---
> >> Changes in v2:
> >> - Matching the BIG handle is required when looking up a BIG connection.
> >> - Use ev->reason to determine the cause of disconnection.
> >> - Call hci_conn_del after hci_disconnect_cfm to remove the connection entry
> >> - Delete the big connection
> >> - Link to v1: https://lore.kernel.org/r/20250624-handle_big_sync_lost_event-v1-1-c32ce37dd6a5@amlogic.com
> >> ---
> >>   include/net/bluetooth/hci.h |  6 ++++++
> >>   net/bluetooth/hci_event.c   | 31 +++++++++++++++++++++++++++++++
> >>   2 files changed, 37 insertions(+)
> >>
> >> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> >> index 82cbd54443ac..48389a64accb 100644
> >> --- a/include/net/bluetooth/hci.h
> >> +++ b/include/net/bluetooth/hci.h
> >> @@ -2849,6 +2849,12 @@ struct hci_evt_le_big_sync_estabilished {
> >>        __le16  bis[];
> >>   } __packed;
> >>
> >> +#define HCI_EVT_LE_BIG_SYNC_LOST 0x1e
> >> +struct hci_evt_le_big_sync_lost {
> >> +     __u8    handle;
> >> +     __u8    reason;
> >> +} __packed;
> >> +
> >>   #define HCI_EVT_LE_BIG_INFO_ADV_REPORT       0x22
> >>   struct hci_evt_le_big_info_adv_report {
> >>        __le16  sync_handle;
> >> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> >> index 66052d6aaa1d..d0b9c8dca891 100644
> >> --- a/net/bluetooth/hci_event.c
> >> +++ b/net/bluetooth/hci_event.c
> >> @@ -7026,6 +7026,32 @@ static void hci_le_big_sync_established_evt(struct hci_dev *hdev, void *data,
> >>        hci_dev_unlock(hdev);
> >>   }
> >>
> >> +static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
> >> +                                         struct sk_buff *skb)
> >> +{
> >> +     struct hci_evt_le_big_sync_lost *ev = data;
> >> +     struct hci_conn *bis, *conn;
> >> +
> >> +     bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
> >> +
> >> +     hci_dev_lock(hdev);
> >> +
> >> +     list_for_each_entry(bis, &hdev->conn_hash.list, list) {
> > This should check bis->type == BIS_LINK too.
> Will do.
> >
> >> +             if (test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags) &&
> >> +                 (bis->iso_qos.bcast.big == ev->handle)) {
> >> +                     hci_disconn_cfm(bis, ev->reason);
> >> +                     hci_conn_del(bis);
> >> +
> >> +                     /* Delete the big connection */
> >> +                     conn = hci_conn_hash_lookup_pa_sync_handle(hdev, bis->sync_handle);
> >> +                     if (conn)
> >> +                             hci_conn_del(conn);
> > Problems:
> >
> > - use after free
> >
> > - hci_conn_del() cannot be used inside list_for_each_entry()
> >    of the connection list
> >
> > - also list_for_each_entry_safe() allows deleting only the iteration
> >    cursor, so some restructuring above is needed
>
> Following your suggestion, I updated the hci_le_big_sync_lost_evt function.
>
> +static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
> +                                           struct sk_buff *skb)
> +{
> +       struct hci_evt_le_big_sync_lost *ev = data;
> +       struct hci_conn *bis, *conn, *n;
> +
> +       bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
> +
> +       hci_dev_lock(hdev);
> +
> +       /* Delete the pa sync connection */
> +       bis = hci_conn_hash_lookup_pa_sync_big_handle(hdev, ev->handle);
> +       if (bis) {
> +               conn = hci_conn_hash_lookup_pa_sync_handle(hdev,
> bis->sync_handle);
> +               if (conn)
> +                       hci_conn_del(conn);
> +       }
> +
> +       /* Delete each bis connection */
> +       list_for_each_entry_safe(bis, n, &hdev->conn_hash.list, list) {
> +               if (bis->type == BIS_LINK &&
> +                   bis->iso_qos.bcast.big == ev->handle &&
> +                   test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags)) {
> +                       hci_disconn_cfm(bis, ev->reason);
> +                       hci_conn_del(bis);
> +               }
> +       }

Id follow the logic in hci_le_create_big_complete_evt, so you do something like:

    while ((conn = hci_conn_hash_lookup_big_state(hdev, ev->handle,
                              BT_CONNECTED)))...

That way we don't operate on the list cursor, that said we may need to
add the role as parameter to hci_conn_hash_lookup_big_state, because
the BIG id domain is role specific so we can have clashes if there are
Broadcast Sources using the same BIG id the above would return them as
well and even if we check for the role inside the while loop will keep
returning it forever.

> +
> +       hci_dev_unlock(hdev);
> +}
>
> >
> >> +             }
> >> +     }
> >> +
> >> +     hci_dev_unlock(hdev);
> >> +}
> >> +
> >>   static void hci_le_big_info_adv_report_evt(struct hci_dev *hdev, void *data,
> >>                                           struct sk_buff *skb)
> >>   {
> >> @@ -7149,6 +7175,11 @@ static const struct hci_le_ev {
> >>                     hci_le_big_sync_established_evt,
> >>                     sizeof(struct hci_evt_le_big_sync_estabilished),
> >>                     HCI_MAX_EVENT_SIZE),
> >> +     /* [0x1e = HCI_EVT_LE_BIG_SYNC_LOST] */
> >> +     HCI_LE_EV_VL(HCI_EVT_LE_BIG_SYNC_LOST,
> >> +                  hci_le_big_sync_lost_evt,
> >> +                  sizeof(struct hci_evt_le_big_sync_lost),
> >> +                  HCI_MAX_EVENT_SIZE),
> >>        /* [0x22 = HCI_EVT_LE_BIG_INFO_ADV_REPORT] */
> >>        HCI_LE_EV_VL(HCI_EVT_LE_BIG_INFO_ADV_REPORT,
> >>                     hci_le_big_info_adv_report_evt,
> >>
> >> ---
> >> base-commit: bd35cd12d915bc410c721ba28afcada16f0ebd16
> >> change-id: 20250612-handle_big_sync_lost_event-4c7dc64390a2
> >>
> >> Best regards,
> > --
> > Pauli Virtanen



-- 
Luiz Augusto von Dentz

Re: [PATCH v2] Bluetooth: hci_event: Add support for handling LE BIG Sync Lost event

[Yang Li]

Hi Luiz,
> [ EXTERNAL EMAIL ]
>
> Hi Yang,
>
> On Thu, Jun 26, 2025 at 1:54 AM Yang Li <yang.li@amlogic.com> wrote:
>> Hi Pauli,
>>> [ EXTERNAL EMAIL ]
>>>
>>> Hi,
>>>
>>> ke, 2025-06-25 kello 16:42 +0800, Yang Li via B4 Relay kirjoitti:
>>>> From: Yang Li <yang.li@amlogic.com>
>>>>
>>>> When the BIS source stops, the controller sends an LE BIG Sync Lost
>>>> event (subevent 0x1E). Currently, this event is not handled, causing
>>>> the BIS stream to remain active in BlueZ and preventing recovery.
>>>>
>>>> Signed-off-by: Yang Li <yang.li@amlogic.com>
>>>> ---
>>>> Changes in v2:
>>>> - Matching the BIG handle is required when looking up a BIG connection.
>>>> - Use ev->reason to determine the cause of disconnection.
>>>> - Call hci_conn_del after hci_disconnect_cfm to remove the connection entry
>>>> - Delete the big connection
>>>> - Link to v1: https://lore.kernel.org/r/20250624-handle_big_sync_lost_event-v1-1-c32ce37dd6a5@amlogic.com
>>>> ---
>>>>    include/net/bluetooth/hci.h |  6 ++++++
>>>>    net/bluetooth/hci_event.c   | 31 +++++++++++++++++++++++++++++++
>>>>    2 files changed, 37 insertions(+)
>>>>
>>>> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
>>>> index 82cbd54443ac..48389a64accb 100644
>>>> --- a/include/net/bluetooth/hci.h
>>>> +++ b/include/net/bluetooth/hci.h
>>>> @@ -2849,6 +2849,12 @@ struct hci_evt_le_big_sync_estabilished {
>>>>         __le16  bis[];
>>>>    } __packed;
>>>>
>>>> +#define HCI_EVT_LE_BIG_SYNC_LOST 0x1e
>>>> +struct hci_evt_le_big_sync_lost {
>>>> +     __u8    handle;
>>>> +     __u8    reason;
>>>> +} __packed;
>>>> +
>>>>    #define HCI_EVT_LE_BIG_INFO_ADV_REPORT       0x22
>>>>    struct hci_evt_le_big_info_adv_report {
>>>>         __le16  sync_handle;
>>>> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
>>>> index 66052d6aaa1d..d0b9c8dca891 100644
>>>> --- a/net/bluetooth/hci_event.c
>>>> +++ b/net/bluetooth/hci_event.c
>>>> @@ -7026,6 +7026,32 @@ static void hci_le_big_sync_established_evt(struct hci_dev *hdev, void *data,
>>>>         hci_dev_unlock(hdev);
>>>>    }
>>>>
>>>> +static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
>>>> +                                         struct sk_buff *skb)
>>>> +{
>>>> +     struct hci_evt_le_big_sync_lost *ev = data;
>>>> +     struct hci_conn *bis, *conn;
>>>> +
>>>> +     bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
>>>> +
>>>> +     hci_dev_lock(hdev);
>>>> +
>>>> +     list_for_each_entry(bis, &hdev->conn_hash.list, list) {
>>> This should check bis->type == BIS_LINK too.
>> Will do.
>>>> +             if (test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags) &&
>>>> +                 (bis->iso_qos.bcast.big == ev->handle)) {
>>>> +                     hci_disconn_cfm(bis, ev->reason);
>>>> +                     hci_conn_del(bis);
>>>> +
>>>> +                     /* Delete the big connection */
>>>> +                     conn = hci_conn_hash_lookup_pa_sync_handle(hdev, bis->sync_handle);
>>>> +                     if (conn)
>>>> +                             hci_conn_del(conn);
>>> Problems:
>>>
>>> - use after free
>>>
>>> - hci_conn_del() cannot be used inside list_for_each_entry()
>>>     of the connection list
>>>
>>> - also list_for_each_entry_safe() allows deleting only the iteration
>>>     cursor, so some restructuring above is needed
>> Following your suggestion, I updated the hci_le_big_sync_lost_evt function.
>>
>> +static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
>> +                                           struct sk_buff *skb)
>> +{
>> +       struct hci_evt_le_big_sync_lost *ev = data;
>> +       struct hci_conn *bis, *conn, *n;
>> +
>> +       bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
>> +
>> +       hci_dev_lock(hdev);
>> +
>> +       /* Delete the pa sync connection */
>> +       bis = hci_conn_hash_lookup_pa_sync_big_handle(hdev, ev->handle);
>> +       if (bis) {
>> +               conn = hci_conn_hash_lookup_pa_sync_handle(hdev,
>> bis->sync_handle);
>> +               if (conn)
>> +                       hci_conn_del(conn);
>> +       }
>> +
>> +       /* Delete each bis connection */
>> +       list_for_each_entry_safe(bis, n, &hdev->conn_hash.list, list) {
>> +               if (bis->type == BIS_LINK &&
>> +                   bis->iso_qos.bcast.big == ev->handle &&
>> +                   test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags)) {
>> +                       hci_disconn_cfm(bis, ev->reason);
>> +                       hci_conn_del(bis);
>> +               }
>> +       }
> Id follow the logic in hci_le_create_big_complete_evt, so you do something like:
>
>      while ((conn = hci_conn_hash_lookup_big_state(hdev, ev->handle,
>                                BT_CONNECTED)))...
>
> That way we don't operate on the list cursor, that said we may need to
> add the role as parameter to hci_conn_hash_lookup_big_state, because
> the BIG id domain is role specific so we can have clashes if there are
> Broadcast Sources using the same BIG id the above would return them as
> well and even if we check for the role inside the while loop will keep
> returning it forever.

I updated the patch according to your suggestion; however, during testing, it resulted in a system panic.

hci_conn_hash_lookup_big_state(struct hci_dev *hdev, __u8 handle,  __u16 state)
  
         list_for_each_entry_rcu(c, &h->list, list) {
                 if (c->type != BIS_LINK || bacmp(&c->dst, BDADDR_ANY) ||
+                       c->role != HCI_ROLE_SLAVE ||
                     c->state != state)
                         continue;

+static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
+                                           struct sk_buff *skb)
+{
+       struct hci_evt_le_big_sync_lost *ev = data;
+       struct hci_conn *bis, *conn;
+
+       bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
+
+       hci_dev_lock(hdev);
+
+       /* Delete the pa sync connection */
+       bis = hci_conn_hash_lookup_pa_sync_big_handle(hdev, ev->handle);
+       if (bis) {
+               conn = hci_conn_hash_lookup_pa_sync_handle(hdev, bis->sync_handle);
+               if (conn)
+                       hci_conn_del(conn);
+       }
+
+       /* Delete each bis connection */
+       while ((bis = hci_conn_hash_lookup_big_state(hdev, ev->handle,
+                                                       BT_CONNECTED))) {
+               clear_bit(HCI_CONN_BIG_SYNC, &bis->flags);
+               hci_disconn_cfm(bis, ev->reason);
+               hci_conn_del(bis);
+       }
+
+       hci_dev_unlock(hdev);
+}

However, during testing, I encountered some issues:

1. The current BIS connections all have the state BT_OPEN (2).

[  131.813237][1 T1967  d.] list conn 00000000fd2e0fb2, handle 0x0010, 
state 1 #LE link
[  131.813439][1 T1967  d.] list conn 00000000553bfedc, handle 0x0f01, 
state 2  #PA link
[  131.814301][1 T1967  d.] list conn 0000000074213ccb, handle 0x0100, 
state 2 #bis1 link
[  131.815167][1 T1967  d.] list conn 00000000ee6adb18, handle 0x0101, 
state 2 #bis2 link

2. hci_conn_hash_lookup_big_state() fails to find the corresponding BIS 
connection even when the state is set to OPEN.

Therefore, I’m considering reverting to the original patch, but adding a 
role check as an additional condition.
What do you think?

+       /* Delete each bis connection */
+       list_for_each_entry_safe(bis, n, &hdev->conn_hash.list, list) {
+               if (bis->type == BIS_LINK &&
+                   bis->role == HCI_ROLE_SLAVE &&
+                   bis->iso_qos.bcast.big == ev->handle &&
+                   test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags)) {
+                       hci_disconn_cfm(bis, ev->reason);
+                       hci_conn_del(bis);
+               }
+       }

>
>> +
>> +       hci_dev_unlock(hdev);
>> +}
>>
>>>> +             }
>>>> +     }
>>>> +
>>>> +     hci_dev_unlock(hdev);
>>>> +}
>>>> +
>>>>    static void hci_le_big_info_adv_report_evt(struct hci_dev *hdev, void *data,
>>>>                                            struct sk_buff *skb)
>>>>    {
>>>> @@ -7149,6 +7175,11 @@ static const struct hci_le_ev {
>>>>                      hci_le_big_sync_established_evt,
>>>>                      sizeof(struct hci_evt_le_big_sync_estabilished),
>>>>                      HCI_MAX_EVENT_SIZE),
>>>> +     /* [0x1e = HCI_EVT_LE_BIG_SYNC_LOST] */
>>>> +     HCI_LE_EV_VL(HCI_EVT_LE_BIG_SYNC_LOST,
>>>> +                  hci_le_big_sync_lost_evt,
>>>> +                  sizeof(struct hci_evt_le_big_sync_lost),
>>>> +                  HCI_MAX_EVENT_SIZE),
>>>>         /* [0x22 = HCI_EVT_LE_BIG_INFO_ADV_REPORT] */
>>>>         HCI_LE_EV_VL(HCI_EVT_LE_BIG_INFO_ADV_REPORT,
>>>>                      hci_le_big_info_adv_report_evt,
>>>>
>>>> ---
>>>> base-commit: bd35cd12d915bc410c721ba28afcada16f0ebd16
>>>> change-id: 20250612-handle_big_sync_lost_event-4c7dc64390a2
>>>>
>>>> Best regards,
>>> --
>>> Pauli Virtanen
>
>
> --
> Luiz Augusto von Dentz

Re: [PATCH v2] Bluetooth: hci_event: Add support for handling LE BIG Sync Lost event

[Luiz Augusto von Dentz]

Hi,

On Fri, Jun 27, 2025 at 7:31 AM Yang Li <yang.li@amlogic.com> wrote:
>
> Hi Luiz,
> > [ EXTERNAL EMAIL ]
> >
> > Hi Yang,
> >
> > On Thu, Jun 26, 2025 at 1:54 AM Yang Li <yang.li@amlogic.com> wrote:
> >> Hi Pauli,
> >>> [ EXTERNAL EMAIL ]
> >>>
> >>> Hi,
> >>>
> >>> ke, 2025-06-25 kello 16:42 +0800, Yang Li via B4 Relay kirjoitti:
> >>>> From: Yang Li <yang.li@amlogic.com>
> >>>>
> >>>> When the BIS source stops, the controller sends an LE BIG Sync Lost
> >>>> event (subevent 0x1E). Currently, this event is not handled, causing
> >>>> the BIS stream to remain active in BlueZ and preventing recovery.
> >>>>
> >>>> Signed-off-by: Yang Li <yang.li@amlogic.com>
> >>>> ---
> >>>> Changes in v2:
> >>>> - Matching the BIG handle is required when looking up a BIG connection.
> >>>> - Use ev->reason to determine the cause of disconnection.
> >>>> - Call hci_conn_del after hci_disconnect_cfm to remove the connection entry
> >>>> - Delete the big connection
> >>>> - Link to v1: https://lore.kernel.org/r/20250624-handle_big_sync_lost_event-v1-1-c32ce37dd6a5@amlogic.com
> >>>> ---
> >>>>    include/net/bluetooth/hci.h |  6 ++++++
> >>>>    net/bluetooth/hci_event.c   | 31 +++++++++++++++++++++++++++++++
> >>>>    2 files changed, 37 insertions(+)
> >>>>
> >>>> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> >>>> index 82cbd54443ac..48389a64accb 100644
> >>>> --- a/include/net/bluetooth/hci.h
> >>>> +++ b/include/net/bluetooth/hci.h
> >>>> @@ -2849,6 +2849,12 @@ struct hci_evt_le_big_sync_estabilished {
> >>>>         __le16  bis[];
> >>>>    } __packed;
> >>>>
> >>>> +#define HCI_EVT_LE_BIG_SYNC_LOST 0x1e
> >>>> +struct hci_evt_le_big_sync_lost {
> >>>> +     __u8    handle;
> >>>> +     __u8    reason;
> >>>> +} __packed;
> >>>> +
> >>>>    #define HCI_EVT_LE_BIG_INFO_ADV_REPORT       0x22
> >>>>    struct hci_evt_le_big_info_adv_report {
> >>>>         __le16  sync_handle;
> >>>> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> >>>> index 66052d6aaa1d..d0b9c8dca891 100644
> >>>> --- a/net/bluetooth/hci_event.c
> >>>> +++ b/net/bluetooth/hci_event.c
> >>>> @@ -7026,6 +7026,32 @@ static void hci_le_big_sync_established_evt(struct hci_dev *hdev, void *data,
> >>>>         hci_dev_unlock(hdev);
> >>>>    }
> >>>>
> >>>> +static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
> >>>> +                                         struct sk_buff *skb)
> >>>> +{
> >>>> +     struct hci_evt_le_big_sync_lost *ev = data;
> >>>> +     struct hci_conn *bis, *conn;
> >>>> +
> >>>> +     bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
> >>>> +
> >>>> +     hci_dev_lock(hdev);
> >>>> +
> >>>> +     list_for_each_entry(bis, &hdev->conn_hash.list, list) {
> >>> This should check bis->type == BIS_LINK too.
> >> Will do.
> >>>> +             if (test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags) &&
> >>>> +                 (bis->iso_qos.bcast.big == ev->handle)) {
> >>>> +                     hci_disconn_cfm(bis, ev->reason);
> >>>> +                     hci_conn_del(bis);
> >>>> +
> >>>> +                     /* Delete the big connection */
> >>>> +                     conn = hci_conn_hash_lookup_pa_sync_handle(hdev, bis->sync_handle);
> >>>> +                     if (conn)
> >>>> +                             hci_conn_del(conn);
> >>> Problems:
> >>>
> >>> - use after free
> >>>
> >>> - hci_conn_del() cannot be used inside list_for_each_entry()
> >>>     of the connection list
> >>>
> >>> - also list_for_each_entry_safe() allows deleting only the iteration
> >>>     cursor, so some restructuring above is needed
> >> Following your suggestion, I updated the hci_le_big_sync_lost_evt function.
> >>
> >> +static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
> >> +                                           struct sk_buff *skb)
> >> +{
> >> +       struct hci_evt_le_big_sync_lost *ev = data;
> >> +       struct hci_conn *bis, *conn, *n;
> >> +
> >> +       bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
> >> +
> >> +       hci_dev_lock(hdev);
> >> +
> >> +       /* Delete the pa sync connection */
> >> +       bis = hci_conn_hash_lookup_pa_sync_big_handle(hdev, ev->handle);
> >> +       if (bis) {
> >> +               conn = hci_conn_hash_lookup_pa_sync_handle(hdev,
> >> bis->sync_handle);
> >> +               if (conn)
> >> +                       hci_conn_del(conn);
> >> +       }
> >> +
> >> +       /* Delete each bis connection */
> >> +       list_for_each_entry_safe(bis, n, &hdev->conn_hash.list, list) {
> >> +               if (bis->type == BIS_LINK &&
> >> +                   bis->iso_qos.bcast.big == ev->handle &&
> >> +                   test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags)) {
> >> +                       hci_disconn_cfm(bis, ev->reason);
> >> +                       hci_conn_del(bis);
> >> +               }
> >> +       }
> > Id follow the logic in hci_le_create_big_complete_evt, so you do something like:
> >
> >      while ((conn = hci_conn_hash_lookup_big_state(hdev, ev->handle,
> >                                BT_CONNECTED)))...
> >
> > That way we don't operate on the list cursor, that said we may need to
> > add the role as parameter to hci_conn_hash_lookup_big_state, because
> > the BIG id domain is role specific so we can have clashes if there are
> > Broadcast Sources using the same BIG id the above would return them as
> > well and even if we check for the role inside the while loop will keep
> > returning it forever.
>
> I updated the patch according to your suggestion; however, during testing, it resulted in a system panic.

What is the backtrace?

> hci_conn_hash_lookup_big_state(struct hci_dev *hdev, __u8 handle,  __u16 state)
>
>          list_for_each_entry_rcu(c, &h->list, list) {
>                  if (c->type != BIS_LINK || bacmp(&c->dst, BDADDR_ANY) ||
> +                       c->role != HCI_ROLE_SLAVE ||
>                      c->state != state)
>                          continue;

It needs to be passed as an argument not just change the role
internally otherwise it will break the existing users of it.

> +static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
> +                                           struct sk_buff *skb)
> +{
> +       struct hci_evt_le_big_sync_lost *ev = data;
> +       struct hci_conn *bis, *conn;
> +
> +       bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
> +
> +       hci_dev_lock(hdev);
> +
> +       /* Delete the pa sync connection */
> +       bis = hci_conn_hash_lookup_pa_sync_big_handle(hdev, ev->handle);
> +       if (bis) {
> +               conn = hci_conn_hash_lookup_pa_sync_handle(hdev, bis->sync_handle);
> +               if (conn)
> +                       hci_conn_del(conn);
> +       }
> +
> +       /* Delete each bis connection */
> +       while ((bis = hci_conn_hash_lookup_big_state(hdev, ev->handle,
> +                                                       BT_CONNECTED))) {
> +               clear_bit(HCI_CONN_BIG_SYNC, &bis->flags);
> +               hci_disconn_cfm(bis, ev->reason);
> +               hci_conn_del(bis);
> +       }
> +
> +       hci_dev_unlock(hdev);
> +}
>
> However, during testing, I encountered some issues:
>
> 1. The current BIS connections all have the state BT_OPEN (2).

Hmm, that doesn't sound right, if the BIG Sync has been completed the
BIS connection shall be moved to BT_CONNECTED. Looks like we are not
marking it as connected:

hci_le_big_sync_established_evt (Broadcast Sink):

        set_bit(HCI_CONN_BIG_SYNC, &bis->flags);
       hci_iso_setup_path(bis);

hci_le_create_big_complete_evt (Broadcast Source):

        conn->state = BT_CONNECTED;
        set_bit(HCI_CONN_BIG_CREATED, &conn->flags);
        hci_debugfs_create_conn(conn);
        hci_conn_add_sysfs(conn);
        hci_iso_setup_path(conn);

> [  131.813237][1 T1967  d.] list conn 00000000fd2e0fb2, handle 0x0010,
> state 1 #LE link
> [  131.813439][1 T1967  d.] list conn 00000000553bfedc, handle 0x0f01,
> state 2  #PA link
> [  131.814301][1 T1967  d.] list conn 0000000074213ccb, handle 0x0100,
> state 2 #bis1 link
> [  131.815167][1 T1967  d.] list conn 00000000ee6adb18, handle 0x0101,
> state 2 #bis2 link
>
> 2. hci_conn_hash_lookup_big_state() fails to find the corresponding BIS
> connection even when the state is set to OPEN.
>
> Therefore, I’m considering reverting to the original patch, but adding a
> role check as an additional condition.
> What do you think?
>
> +       /* Delete each bis connection */
> +       list_for_each_entry_safe(bis, n, &hdev->conn_hash.list, list) {
> +               if (bis->type == BIS_LINK &&
> +                   bis->role == HCI_ROLE_SLAVE &&
> +                   bis->iso_qos.bcast.big == ev->handle &&
> +                   test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags)) {
> +                       hci_disconn_cfm(bis, ev->reason);
> +                       hci_conn_del(bis);
> +               }
> +       }
>
> >
> >> +
> >> +       hci_dev_unlock(hdev);
> >> +}
> >>
> >>>> +             }
> >>>> +     }
> >>>> +
> >>>> +     hci_dev_unlock(hdev);
> >>>> +}
> >>>> +
> >>>>    static void hci_le_big_info_adv_report_evt(struct hci_dev *hdev, void *data,
> >>>>                                            struct sk_buff *skb)
> >>>>    {
> >>>> @@ -7149,6 +7175,11 @@ static const struct hci_le_ev {
> >>>>                      hci_le_big_sync_established_evt,
> >>>>                      sizeof(struct hci_evt_le_big_sync_estabilished),
> >>>>                      HCI_MAX_EVENT_SIZE),
> >>>> +     /* [0x1e = HCI_EVT_LE_BIG_SYNC_LOST] */
> >>>> +     HCI_LE_EV_VL(HCI_EVT_LE_BIG_SYNC_LOST,
> >>>> +                  hci_le_big_sync_lost_evt,
> >>>> +                  sizeof(struct hci_evt_le_big_sync_lost),
> >>>> +                  HCI_MAX_EVENT_SIZE),
> >>>>         /* [0x22 = HCI_EVT_LE_BIG_INFO_ADV_REPORT] */
> >>>>         HCI_LE_EV_VL(HCI_EVT_LE_BIG_INFO_ADV_REPORT,
> >>>>                      hci_le_big_info_adv_report_evt,
> >>>>
> >>>> ---
> >>>> base-commit: bd35cd12d915bc410c721ba28afcada16f0ebd16
> >>>> change-id: 20250612-handle_big_sync_lost_event-4c7dc64390a2
> >>>>
> >>>> Best regards,
> >>> --
> >>> Pauli Virtanen
> >
> >
> > --
> > Luiz Augusto von Dentz



-- 
Luiz Augusto von Dentz

Re: [PATCH v2] Bluetooth: hci_event: Add support for handling LE BIG Sync Lost event

[Yang Li]

Hi,
> [ EXTERNAL EMAIL ]
>
> Hi,
>
> On Fri, Jun 27, 2025 at 7:31 AM Yang Li <yang.li@amlogic.com> wrote:
>> Hi Luiz,
>>> [ EXTERNAL EMAIL ]
>>>
>>> Hi Yang,
>>>
>>> On Thu, Jun 26, 2025 at 1:54 AM Yang Li <yang.li@amlogic.com> wrote:
>>>> Hi Pauli,
>>>>> [ EXTERNAL EMAIL ]
>>>>>
>>>>> Hi,
>>>>>
>>>>> ke, 2025-06-25 kello 16:42 +0800, Yang Li via B4 Relay kirjoitti:
>>>>>> From: Yang Li <yang.li@amlogic.com>
>>>>>>
>>>>>> When the BIS source stops, the controller sends an LE BIG Sync Lost
>>>>>> event (subevent 0x1E). Currently, this event is not handled, causing
>>>>>> the BIS stream to remain active in BlueZ and preventing recovery.
>>>>>>
>>>>>> Signed-off-by: Yang Li <yang.li@amlogic.com>
>>>>>> ---
>>>>>> Changes in v2:
>>>>>> - Matching the BIG handle is required when looking up a BIG connection.
>>>>>> - Use ev->reason to determine the cause of disconnection.
>>>>>> - Call hci_conn_del after hci_disconnect_cfm to remove the connection entry
>>>>>> - Delete the big connection
>>>>>> - Link to v1: https://lore.kernel.org/r/20250624-handle_big_sync_lost_event-v1-1-c32ce37dd6a5@amlogic.com
>>>>>> ---
>>>>>>     include/net/bluetooth/hci.h |  6 ++++++
>>>>>>     net/bluetooth/hci_event.c   | 31 +++++++++++++++++++++++++++++++
>>>>>>     2 files changed, 37 insertions(+)
>>>>>>
>>>>>> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
>>>>>> index 82cbd54443ac..48389a64accb 100644
>>>>>> --- a/include/net/bluetooth/hci.h
>>>>>> +++ b/include/net/bluetooth/hci.h
>>>>>> @@ -2849,6 +2849,12 @@ struct hci_evt_le_big_sync_estabilished {
>>>>>>          __le16  bis[];
>>>>>>     } __packed;
>>>>>>
>>>>>> +#define HCI_EVT_LE_BIG_SYNC_LOST 0x1e
>>>>>> +struct hci_evt_le_big_sync_lost {
>>>>>> +     __u8    handle;
>>>>>> +     __u8    reason;
>>>>>> +} __packed;
>>>>>> +
>>>>>>     #define HCI_EVT_LE_BIG_INFO_ADV_REPORT       0x22
>>>>>>     struct hci_evt_le_big_info_adv_report {
>>>>>>          __le16  sync_handle;
>>>>>> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
>>>>>> index 66052d6aaa1d..d0b9c8dca891 100644
>>>>>> --- a/net/bluetooth/hci_event.c
>>>>>> +++ b/net/bluetooth/hci_event.c
>>>>>> @@ -7026,6 +7026,32 @@ static void hci_le_big_sync_established_evt(struct hci_dev *hdev, void *data,
>>>>>>          hci_dev_unlock(hdev);
>>>>>>     }
>>>>>>
>>>>>> +static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
>>>>>> +                                         struct sk_buff *skb)
>>>>>> +{
>>>>>> +     struct hci_evt_le_big_sync_lost *ev = data;
>>>>>> +     struct hci_conn *bis, *conn;
>>>>>> +
>>>>>> +     bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
>>>>>> +
>>>>>> +     hci_dev_lock(hdev);
>>>>>> +
>>>>>> +     list_for_each_entry(bis, &hdev->conn_hash.list, list) {
>>>>> This should check bis->type == BIS_LINK too.
>>>> Will do.
>>>>>> +             if (test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags) &&
>>>>>> +                 (bis->iso_qos.bcast.big == ev->handle)) {
>>>>>> +                     hci_disconn_cfm(bis, ev->reason);
>>>>>> +                     hci_conn_del(bis);
>>>>>> +
>>>>>> +                     /* Delete the big connection */
>>>>>> +                     conn = hci_conn_hash_lookup_pa_sync_handle(hdev, bis->sync_handle);
>>>>>> +                     if (conn)
>>>>>> +                             hci_conn_del(conn);
>>>>> Problems:
>>>>>
>>>>> - use after free
>>>>>
>>>>> - hci_conn_del() cannot be used inside list_for_each_entry()
>>>>>      of the connection list
>>>>>
>>>>> - also list_for_each_entry_safe() allows deleting only the iteration
>>>>>      cursor, so some restructuring above is needed
>>>> Following your suggestion, I updated the hci_le_big_sync_lost_evt function.
>>>>
>>>> +static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
>>>> +                                           struct sk_buff *skb)
>>>> +{
>>>> +       struct hci_evt_le_big_sync_lost *ev = data;
>>>> +       struct hci_conn *bis, *conn, *n;
>>>> +
>>>> +       bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
>>>> +
>>>> +       hci_dev_lock(hdev);
>>>> +
>>>> +       /* Delete the pa sync connection */
>>>> +       bis = hci_conn_hash_lookup_pa_sync_big_handle(hdev, ev->handle);
>>>> +       if (bis) {
>>>> +               conn = hci_conn_hash_lookup_pa_sync_handle(hdev,
>>>> bis->sync_handle);
>>>> +               if (conn)
>>>> +                       hci_conn_del(conn);
>>>> +       }
>>>> +
>>>> +       /* Delete each bis connection */
>>>> +       list_for_each_entry_safe(bis, n, &hdev->conn_hash.list, list) {
>>>> +               if (bis->type == BIS_LINK &&
>>>> +                   bis->iso_qos.bcast.big == ev->handle &&
>>>> +                   test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags)) {
>>>> +                       hci_disconn_cfm(bis, ev->reason);
>>>> +                       hci_conn_del(bis);
>>>> +               }
>>>> +       }
>>> Id follow the logic in hci_le_create_big_complete_evt, so you do something like:
>>>
>>>       while ((conn = hci_conn_hash_lookup_big_state(hdev, ev->handle,
>>>                                 BT_CONNECTED)))...
>>>
>>> That way we don't operate on the list cursor, that said we may need to
>>> add the role as parameter to hci_conn_hash_lookup_big_state, because
>>> the BIG id domain is role specific so we can have clashes if there are
>>> Broadcast Sources using the same BIG id the above would return them as
>>> well and even if we check for the role inside the while loop will keep
>>> returning it forever.
>> I updated the patch according to your suggestion; however, during testing, it resulted in a system panic.
> What is the backtrace?
>
>> hci_conn_hash_lookup_big_state(struct hci_dev *hdev, __u8 handle,  __u16 state)
>>
>>           list_for_each_entry_rcu(c, &h->list, list) {
>>                   if (c->type != BIS_LINK || bacmp(&c->dst, BDADDR_ANY) ||
>> +                       c->role != HCI_ROLE_SLAVE ||
>>                       c->state != state)
>>                           continue;
> It needs to be passed as an argument not just change the role
> internally otherwise it will break the existing users of it.

After testing, I found that the dst addr of the two BIS connections 
under BIG sync is the address of the BIS source, so I added separate 
checks for MASTER and SLAVE roles.

[  268.202466][1 T1962  d.] lookup big: 00000000736585c7, addr 
21:97:07:b1:9f:66, type 131, handle 0x0100, state 1, role 1
[  268.203806][1 T1962  d.] lookup big: 0000000041894659, addr 
21:97:07:b1:9f:66, type 131, handle 0x0101, state 1, role 1

I updated as below,

-hci_conn_hash_lookup_big_state(struct hci_dev *hdev, __u8 handle,  
__u16 state)
+hci_conn_hash_lookup_big_state(struct hci_dev *hdev, __u8 handle,
+                                                 __u16 state, __u8 role)
  {
         struct hci_conn_hash *h = &hdev->conn_hash;
         struct hci_conn  *c;
@@ -1335,10 +1336,18 @@ hci_conn_hash_lookup_big_state(struct hci_dev 
*hdev, __u8 handle,  __u16 state)
         rcu_read_lock();

         list_for_each_entry_rcu(c, &h->list, list) {
-               if (c->type != BIS_LINK || bacmp(&c->dst, BDADDR_ANY) ||
-                       c->role != HCI_ROLE_SLAVE ||
-                   c->state != state)
-                       continue;
+               if (role == HCI_ROLE_MASTER) {
+                       if (c->type != BIS_LINK || bacmp(&c->dst, 
BDADDR_ANY) ||
+                               c->state != state || c->role != role)
+                               continue;
+               } else {
+                       if (c->type != BIS_LINK ||
+                               c->state != state ||
+                               c->role != role)
+                               continue;
+               }

>
>> +static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
>> +                                           struct sk_buff *skb)
>> +{
>> +       struct hci_evt_le_big_sync_lost *ev = data;
>> +       struct hci_conn *bis, *conn;
>> +
>> +       bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
>> +
>> +       hci_dev_lock(hdev);
>> +
>> +       /* Delete the pa sync connection */
>> +       bis = hci_conn_hash_lookup_pa_sync_big_handle(hdev, ev->handle);
>> +       if (bis) {
>> +               conn = hci_conn_hash_lookup_pa_sync_handle(hdev, bis->sync_handle);
>> +               if (conn)
>> +                       hci_conn_del(conn);
>> +       }
>> +
>> +       /* Delete each bis connection */
>> +       while ((bis = hci_conn_hash_lookup_big_state(hdev, ev->handle,
>> +                                                       BT_CONNECTED))) {
>> +               clear_bit(HCI_CONN_BIG_SYNC, &bis->flags);
>> +               hci_disconn_cfm(bis, ev->reason);
>> +               hci_conn_del(bis);
>> +       }
>> +
>> +       hci_dev_unlock(hdev);
>> +}
>>
>> However, during testing, I encountered some issues:
>>
>> 1. The current BIS connections all have the state BT_OPEN (2).
> Hmm, that doesn't sound right, if the BIG Sync has been completed the
> BIS connection shall be moved to BT_CONNECTED. Looks like we are not
> marking it as connected:
>
> hci_le_big_sync_established_evt (Broadcast Sink):
>
>          set_bit(HCI_CONN_BIG_SYNC, &bis->flags);
>         hci_iso_setup_path(bis);
>
> hci_le_create_big_complete_evt (Broadcast Source):
>
>          conn->state = BT_CONNECTED;
>          set_bit(HCI_CONN_BIG_CREATED, &conn->flags);
>          hci_debugfs_create_conn(conn);
>          hci_conn_add_sysfs(conn);
>          hci_iso_setup_path(conn);

Yes, in addition, state = BT_CONNECTED also needs to be set in 
hci_cc_le_setup_iso_path.

I will update the patch again.

@@ -3890,7 +3890,7 @@ static u8 hci_cc_le_setup_iso_path(struct hci_dev 
*hdev, void *data,
                 hci_conn_del(conn);
                 goto unlock;
         }
-
+     conn->state = BT_CONNECTED;

>> [  131.813237][1 T1967  d.] list conn 00000000fd2e0fb2, handle 0x0010,
>> state 1 #LE link
>> [  131.813439][1 T1967  d.] list conn 00000000553bfedc, handle 0x0f01,
>> state 2  #PA link
>> [  131.814301][1 T1967  d.] list conn 0000000074213ccb, handle 0x0100,
>> state 2 #bis1 link
>> [  131.815167][1 T1967  d.] list conn 00000000ee6adb18, handle 0x0101,
>> state 2 #bis2 link
>>
>> 2. hci_conn_hash_lookup_big_state() fails to find the corresponding BIS
>> connection even when the state is set to OPEN.
>>
>> Therefore, I’m considering reverting to the original patch, but adding a
>> role check as an additional condition.
>> What do you think?
>>
>> +       /* Delete each bis connection */
>> +       list_for_each_entry_safe(bis, n, &hdev->conn_hash.list, list) {
>> +               if (bis->type == BIS_LINK &&
>> +                   bis->role == HCI_ROLE_SLAVE &&
>> +                   bis->iso_qos.bcast.big == ev->handle &&
>> +                   test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags)) {
>> +                       hci_disconn_cfm(bis, ev->reason);
>> +                       hci_conn_del(bis);
>> +               }
>> +       }
>>
>>>> +
>>>> +       hci_dev_unlock(hdev);
>>>> +}
>>>>
>>>>>> +             }
>>>>>> +     }
>>>>>> +
>>>>>> +     hci_dev_unlock(hdev);
>>>>>> +}
>>>>>> +
>>>>>>     static void hci_le_big_info_adv_report_evt(struct hci_dev *hdev, void *data,
>>>>>>                                             struct sk_buff *skb)
>>>>>>     {
>>>>>> @@ -7149,6 +7175,11 @@ static const struct hci_le_ev {
>>>>>>                       hci_le_big_sync_established_evt,
>>>>>>                       sizeof(struct hci_evt_le_big_sync_estabilished),
>>>>>>                       HCI_MAX_EVENT_SIZE),
>>>>>> +     /* [0x1e = HCI_EVT_LE_BIG_SYNC_LOST] */
>>>>>> +     HCI_LE_EV_VL(HCI_EVT_LE_BIG_SYNC_LOST,
>>>>>> +                  hci_le_big_sync_lost_evt,
>>>>>> +                  sizeof(struct hci_evt_le_big_sync_lost),
>>>>>> +                  HCI_MAX_EVENT_SIZE),
>>>>>>          /* [0x22 = HCI_EVT_LE_BIG_INFO_ADV_REPORT] */
>>>>>>          HCI_LE_EV_VL(HCI_EVT_LE_BIG_INFO_ADV_REPORT,
>>>>>>                       hci_le_big_info_adv_report_evt,
>>>>>>
>>>>>> ---
>>>>>> base-commit: bd35cd12d915bc410c721ba28afcada16f0ebd16
>>>>>> change-id: 20250612-handle_big_sync_lost_event-4c7dc64390a2
>>>>>>
>>>>>> Best regards,
>>>>> --
>>>>> Pauli Virtanen
>>>
>>> --
>>> Luiz Augusto von Dentz
>
>
> --
> Luiz Augusto von Dentz

Re: [PATCH v2] Bluetooth: hci_event: Add support for handling LE BIG Sync Lost event

[Luiz Augusto von Dentz]

Hi,

On Mon, Jun 30, 2025 at 2:15 AM Yang Li <yang.li@amlogic.com> wrote:
>
> Hi,
> > [ EXTERNAL EMAIL ]
> >
> > Hi,
> >
> > On Fri, Jun 27, 2025 at 7:31 AM Yang Li <yang.li@amlogic.com> wrote:
> >> Hi Luiz,
> >>> [ EXTERNAL EMAIL ]
> >>>
> >>> Hi Yang,
> >>>
> >>> On Thu, Jun 26, 2025 at 1:54 AM Yang Li <yang.li@amlogic.com> wrote:
> >>>> Hi Pauli,
> >>>>> [ EXTERNAL EMAIL ]
> >>>>>
> >>>>> Hi,
> >>>>>
> >>>>> ke, 2025-06-25 kello 16:42 +0800, Yang Li via B4 Relay kirjoitti:
> >>>>>> From: Yang Li <yang.li@amlogic.com>
> >>>>>>
> >>>>>> When the BIS source stops, the controller sends an LE BIG Sync Lost
> >>>>>> event (subevent 0x1E). Currently, this event is not handled, causing
> >>>>>> the BIS stream to remain active in BlueZ and preventing recovery.
> >>>>>>
> >>>>>> Signed-off-by: Yang Li <yang.li@amlogic.com>
> >>>>>> ---
> >>>>>> Changes in v2:
> >>>>>> - Matching the BIG handle is required when looking up a BIG connection.
> >>>>>> - Use ev->reason to determine the cause of disconnection.
> >>>>>> - Call hci_conn_del after hci_disconnect_cfm to remove the connection entry
> >>>>>> - Delete the big connection
> >>>>>> - Link to v1: https://lore.kernel.org/r/20250624-handle_big_sync_lost_event-v1-1-c32ce37dd6a5@amlogic.com
> >>>>>> ---
> >>>>>>     include/net/bluetooth/hci.h |  6 ++++++
> >>>>>>     net/bluetooth/hci_event.c   | 31 +++++++++++++++++++++++++++++++
> >>>>>>     2 files changed, 37 insertions(+)
> >>>>>>
> >>>>>> diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
> >>>>>> index 82cbd54443ac..48389a64accb 100644
> >>>>>> --- a/include/net/bluetooth/hci.h
> >>>>>> +++ b/include/net/bluetooth/hci.h
> >>>>>> @@ -2849,6 +2849,12 @@ struct hci_evt_le_big_sync_estabilished {
> >>>>>>          __le16  bis[];
> >>>>>>     } __packed;
> >>>>>>
> >>>>>> +#define HCI_EVT_LE_BIG_SYNC_LOST 0x1e
> >>>>>> +struct hci_evt_le_big_sync_lost {
> >>>>>> +     __u8    handle;
> >>>>>> +     __u8    reason;
> >>>>>> +} __packed;
> >>>>>> +
> >>>>>>     #define HCI_EVT_LE_BIG_INFO_ADV_REPORT       0x22
> >>>>>>     struct hci_evt_le_big_info_adv_report {
> >>>>>>          __le16  sync_handle;
> >>>>>> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> >>>>>> index 66052d6aaa1d..d0b9c8dca891 100644
> >>>>>> --- a/net/bluetooth/hci_event.c
> >>>>>> +++ b/net/bluetooth/hci_event.c
> >>>>>> @@ -7026,6 +7026,32 @@ static void hci_le_big_sync_established_evt(struct hci_dev *hdev, void *data,
> >>>>>>          hci_dev_unlock(hdev);
> >>>>>>     }
> >>>>>>
> >>>>>> +static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
> >>>>>> +                                         struct sk_buff *skb)
> >>>>>> +{
> >>>>>> +     struct hci_evt_le_big_sync_lost *ev = data;
> >>>>>> +     struct hci_conn *bis, *conn;
> >>>>>> +
> >>>>>> +     bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
> >>>>>> +
> >>>>>> +     hci_dev_lock(hdev);
> >>>>>> +
> >>>>>> +     list_for_each_entry(bis, &hdev->conn_hash.list, list) {
> >>>>> This should check bis->type == BIS_LINK too.
> >>>> Will do.
> >>>>>> +             if (test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags) &&
> >>>>>> +                 (bis->iso_qos.bcast.big == ev->handle)) {
> >>>>>> +                     hci_disconn_cfm(bis, ev->reason);
> >>>>>> +                     hci_conn_del(bis);
> >>>>>> +
> >>>>>> +                     /* Delete the big connection */
> >>>>>> +                     conn = hci_conn_hash_lookup_pa_sync_handle(hdev, bis->sync_handle);
> >>>>>> +                     if (conn)
> >>>>>> +                             hci_conn_del(conn);
> >>>>> Problems:
> >>>>>
> >>>>> - use after free
> >>>>>
> >>>>> - hci_conn_del() cannot be used inside list_for_each_entry()
> >>>>>      of the connection list
> >>>>>
> >>>>> - also list_for_each_entry_safe() allows deleting only the iteration
> >>>>>      cursor, so some restructuring above is needed
> >>>> Following your suggestion, I updated the hci_le_big_sync_lost_evt function.
> >>>>
> >>>> +static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
> >>>> +                                           struct sk_buff *skb)
> >>>> +{
> >>>> +       struct hci_evt_le_big_sync_lost *ev = data;
> >>>> +       struct hci_conn *bis, *conn, *n;
> >>>> +
> >>>> +       bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
> >>>> +
> >>>> +       hci_dev_lock(hdev);
> >>>> +
> >>>> +       /* Delete the pa sync connection */
> >>>> +       bis = hci_conn_hash_lookup_pa_sync_big_handle(hdev, ev->handle);
> >>>> +       if (bis) {
> >>>> +               conn = hci_conn_hash_lookup_pa_sync_handle(hdev,
> >>>> bis->sync_handle);
> >>>> +               if (conn)
> >>>> +                       hci_conn_del(conn);
> >>>> +       }
> >>>> +
> >>>> +       /* Delete each bis connection */
> >>>> +       list_for_each_entry_safe(bis, n, &hdev->conn_hash.list, list) {
> >>>> +               if (bis->type == BIS_LINK &&
> >>>> +                   bis->iso_qos.bcast.big == ev->handle &&
> >>>> +                   test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags)) {
> >>>> +                       hci_disconn_cfm(bis, ev->reason);
> >>>> +                       hci_conn_del(bis);
> >>>> +               }
> >>>> +       }
> >>> Id follow the logic in hci_le_create_big_complete_evt, so you do something like:
> >>>
> >>>       while ((conn = hci_conn_hash_lookup_big_state(hdev, ev->handle,
> >>>                                 BT_CONNECTED)))...
> >>>
> >>> That way we don't operate on the list cursor, that said we may need to
> >>> add the role as parameter to hci_conn_hash_lookup_big_state, because
> >>> the BIG id domain is role specific so we can have clashes if there are
> >>> Broadcast Sources using the same BIG id the above would return them as
> >>> well and even if we check for the role inside the while loop will keep
> >>> returning it forever.
> >> I updated the patch according to your suggestion; however, during testing, it resulted in a system panic.
> > What is the backtrace?
> >
> >> hci_conn_hash_lookup_big_state(struct hci_dev *hdev, __u8 handle,  __u16 state)
> >>
> >>           list_for_each_entry_rcu(c, &h->list, list) {
> >>                   if (c->type != BIS_LINK || bacmp(&c->dst, BDADDR_ANY) ||
> >> +                       c->role != HCI_ROLE_SLAVE ||
> >>                       c->state != state)
> >>                           continue;
> > It needs to be passed as an argument not just change the role
> > internally otherwise it will break the existing users of it.
>
> After testing, I found that the dst addr of the two BIS connections
> under BIG sync is the address of the BIS source, so I added separate
> checks for MASTER and SLAVE roles.
>
> [  268.202466][1 T1962  d.] lookup big: 00000000736585c7, addr
> 21:97:07:b1:9f:66, type 131, handle 0x0100, state 1, role 1
> [  268.203806][1 T1962  d.] lookup big: 0000000041894659, addr
> 21:97:07:b1:9f:66, type 131, handle 0x0101, state 1, role 1
>
> I updated as below,
>
> -hci_conn_hash_lookup_big_state(struct hci_dev *hdev, __u8 handle,
> __u16 state)
> +hci_conn_hash_lookup_big_state(struct hci_dev *hdev, __u8 handle,
> +                                                 __u16 state, __u8 role)
>   {
>          struct hci_conn_hash *h = &hdev->conn_hash;
>          struct hci_conn  *c;
> @@ -1335,10 +1336,18 @@ hci_conn_hash_lookup_big_state(struct hci_dev
> *hdev, __u8 handle,  __u16 state)
>          rcu_read_lock();
>
>          list_for_each_entry_rcu(c, &h->list, list) {
> -               if (c->type != BIS_LINK || bacmp(&c->dst, BDADDR_ANY) ||
> -                       c->role != HCI_ROLE_SLAVE ||
> -                   c->state != state)
> -                       continue;
> +               if (role == HCI_ROLE_MASTER) {
> +                       if (c->type != BIS_LINK || bacmp(&c->dst,
> BDADDR_ANY) ||
> +                               c->state != state || c->role != role)
> +                               continue;
> +               } else {
> +                       if (c->type != BIS_LINK ||
> +                               c->state != state ||
> +                               c->role != role)
> +                               continue;
> +               }
>
> >
> >> +static void hci_le_big_sync_lost_evt(struct hci_dev *hdev, void *data,
> >> +                                           struct sk_buff *skb)
> >> +{
> >> +       struct hci_evt_le_big_sync_lost *ev = data;
> >> +       struct hci_conn *bis, *conn;
> >> +
> >> +       bt_dev_dbg(hdev, "big handle 0x%2.2x", ev->handle);
> >> +
> >> +       hci_dev_lock(hdev);
> >> +
> >> +       /* Delete the pa sync connection */
> >> +       bis = hci_conn_hash_lookup_pa_sync_big_handle(hdev, ev->handle);
> >> +       if (bis) {
> >> +               conn = hci_conn_hash_lookup_pa_sync_handle(hdev, bis->sync_handle);
> >> +               if (conn)
> >> +                       hci_conn_del(conn);
> >> +       }
> >> +
> >> +       /* Delete each bis connection */
> >> +       while ((bis = hci_conn_hash_lookup_big_state(hdev, ev->handle,
> >> +                                                       BT_CONNECTED))) {
> >> +               clear_bit(HCI_CONN_BIG_SYNC, &bis->flags);
> >> +               hci_disconn_cfm(bis, ev->reason);
> >> +               hci_conn_del(bis);
> >> +       }
> >> +
> >> +       hci_dev_unlock(hdev);
> >> +}
> >>
> >> However, during testing, I encountered some issues:
> >>
> >> 1. The current BIS connections all have the state BT_OPEN (2).
> > Hmm, that doesn't sound right, if the BIG Sync has been completed the
> > BIS connection shall be moved to BT_CONNECTED. Looks like we are not
> > marking it as connected:
> >
> > hci_le_big_sync_established_evt (Broadcast Sink):
> >
> >          set_bit(HCI_CONN_BIG_SYNC, &bis->flags);
> >         hci_iso_setup_path(bis);
> >
> > hci_le_create_big_complete_evt (Broadcast Source):
> >
> >          conn->state = BT_CONNECTED;
> >          set_bit(HCI_CONN_BIG_CREATED, &conn->flags);
> >          hci_debugfs_create_conn(conn);
> >          hci_conn_add_sysfs(conn);
> >          hci_iso_setup_path(conn);
>
> Yes, in addition, state = BT_CONNECTED also needs to be set in
> hci_cc_le_setup_iso_path.
>
> I will update the patch again.
>
> @@ -3890,7 +3890,7 @@ static u8 hci_cc_le_setup_iso_path(struct hci_dev
> *hdev, void *data,
>                  hci_conn_del(conn);
>                  goto unlock;
>          }
> -
> +     conn->state = BT_CONNECTED;

Ive submitted a fix addressing this already:

https://patchwork.kernel.org/project/bluetooth/patch/20250627151902.421666-1-luiz.dentz@gmail.com/

> >> [  131.813237][1 T1967  d.] list conn 00000000fd2e0fb2, handle 0x0010,
> >> state 1 #LE link
> >> [  131.813439][1 T1967  d.] list conn 00000000553bfedc, handle 0x0f01,
> >> state 2  #PA link
> >> [  131.814301][1 T1967  d.] list conn 0000000074213ccb, handle 0x0100,
> >> state 2 #bis1 link
> >> [  131.815167][1 T1967  d.] list conn 00000000ee6adb18, handle 0x0101,
> >> state 2 #bis2 link
> >>
> >> 2. hci_conn_hash_lookup_big_state() fails to find the corresponding BIS
> >> connection even when the state is set to OPEN.
> >>
> >> Therefore, I’m considering reverting to the original patch, but adding a
> >> role check as an additional condition.
> >> What do you think?
> >>
> >> +       /* Delete each bis connection */
> >> +       list_for_each_entry_safe(bis, n, &hdev->conn_hash.list, list) {
> >> +               if (bis->type == BIS_LINK &&
> >> +                   bis->role == HCI_ROLE_SLAVE &&
> >> +                   bis->iso_qos.bcast.big == ev->handle &&
> >> +                   test_and_clear_bit(HCI_CONN_BIG_SYNC, &bis->flags)) {
> >> +                       hci_disconn_cfm(bis, ev->reason);
> >> +                       hci_conn_del(bis);
> >> +               }
> >> +       }
> >>
> >>>> +
> >>>> +       hci_dev_unlock(hdev);
> >>>> +}
> >>>>
> >>>>>> +             }
> >>>>>> +     }
> >>>>>> +
> >>>>>> +     hci_dev_unlock(hdev);
> >>>>>> +}
> >>>>>> +
> >>>>>>     static void hci_le_big_info_adv_report_evt(struct hci_dev *hdev, void *data,
> >>>>>>                                             struct sk_buff *skb)
> >>>>>>     {
> >>>>>> @@ -7149,6 +7175,11 @@ static const struct hci_le_ev {
> >>>>>>                       hci_le_big_sync_established_evt,
> >>>>>>                       sizeof(struct hci_evt_le_big_sync_estabilished),
> >>>>>>                       HCI_MAX_EVENT_SIZE),
> >>>>>> +     /* [0x1e = HCI_EVT_LE_BIG_SYNC_LOST] */
> >>>>>> +     HCI_LE_EV_VL(HCI_EVT_LE_BIG_SYNC_LOST,
> >>>>>> +                  hci_le_big_sync_lost_evt,
> >>>>>> +                  sizeof(struct hci_evt_le_big_sync_lost),
> >>>>>> +                  HCI_MAX_EVENT_SIZE),
> >>>>>>          /* [0x22 = HCI_EVT_LE_BIG_INFO_ADV_REPORT] */
> >>>>>>          HCI_LE_EV_VL(HCI_EVT_LE_BIG_INFO_ADV_REPORT,
> >>>>>>                       hci_le_big_info_adv_report_evt,
> >>>>>>
> >>>>>> ---
> >>>>>> base-commit: bd35cd12d915bc410c721ba28afcada16f0ebd16
> >>>>>> change-id: 20250612-handle_big_sync_lost_event-4c7dc64390a2
> >>>>>>
> >>>>>> Best regards,
> >>>>> --
> >>>>> Pauli Virtanen
> >>>
> >>> --
> >>> Luiz Augusto von Dentz
> >
> >
> > --
> > Luiz Augusto von Dentz



-- 
Luiz Augusto von Dentz