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[PATCH] Bluetooth: hci_sync: use HCI_CMD_TIMEOUT for PA sync commands

Yang Li via B4 Relay posted 1 patch 1 month ago 
net/bluetooth/hci_sync.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
[PATCH] Bluetooth: hci_sync: use HCI_CMD_TIMEOUT for PA sync commands
Posted by Yang Li via B4 Relay 1 month ago 
From: Yang Li <yang.li@amlogic.com>

PA sync HCI commands incorrectly use conn->conn_timeout, which defaults
to 20s and is too long. If the PA Sync Established event is not
received, the command remains pending and causes userspace timeouts.

Signed-off-by: Yang Li <yang.li@amlogic.com>
---
 net/bluetooth/hci_sync.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index f04a90bce4a9..58292b01f062 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -7159,7 +7159,7 @@ static int hci_le_pa_create_sync(struct hci_dev *hdev, void *data)
 	if (conn->sid == HCI_SID_INVALID) {
 		err = __hci_cmd_sync_status_sk(hdev, HCI_OP_NOP, 0, NULL,
 					       HCI_EV_LE_EXT_ADV_REPORT,
-					       conn->conn_timeout, NULL);
+					       HCI_CMD_TIMEOUT, NULL);
 		if (err == -ETIMEDOUT)
 			goto done;
 	}
@@ -7187,7 +7187,7 @@ static int hci_le_pa_create_sync(struct hci_dev *hdev, void *data)
 	err = __hci_cmd_sync_status_sk(hdev, HCI_OP_LE_PA_CREATE_SYNC,
 				       sizeof(cp), &cp,
 				       HCI_EV_LE_PA_SYNC_ESTABLISHED,
-				       conn->conn_timeout, NULL);
+				       HCI_CMD_TIMEOUT, NULL);
 	if (err == -ETIMEDOUT)
 		__hci_cmd_sync_status(hdev, HCI_OP_LE_PA_CREATE_SYNC_CANCEL,
 				      0, NULL, HCI_CMD_TIMEOUT);

---
base-commit: bdb9aba465a85122bcba01a6154e237b9843e25b
change-id: 20260108-pa_sync_cmd_timeout-ff46f67b5d2a

Best regards,
-- 
Yang Li <yang.li@amlogic.com>
Re: [PATCH] Bluetooth: hci_sync: use HCI_CMD_TIMEOUT for PA sync commands
Posted by Luiz Augusto von Dentz 1 month ago 
Hi Yang,

On Thu, Jan 8, 2026 at 1:03 AM Yang Li via B4 Relay
<devnull+yang.li.amlogic.com@kernel.org> wrote:
>
> From: Yang Li <yang.li@amlogic.com>
>
> PA sync HCI commands incorrectly use conn->conn_timeout, which defaults
> to 20s and is too long. If the PA Sync Established event is not
> received, the command remains pending and causes userspace timeouts.

Im pretty sure this is impossible scenario with bluetooth-next, since
1. only one work can be running hci_le_pa_create_sync at time so
HCI_EV_LE_PA_SYNC_ESTABLISHED cannot be outstanding 2. The
conn->timeout shall be aligned with socket timeout so perhaps the
problem is userspace is not setting the socket timeout correctly or
something.

> Signed-off-by: Yang Li <yang.li@amlogic.com>
> ---
>  net/bluetooth/hci_sync.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
> index f04a90bce4a9..58292b01f062 100644
> --- a/net/bluetooth/hci_sync.c
> +++ b/net/bluetooth/hci_sync.c
> @@ -7159,7 +7159,7 @@ static int hci_le_pa_create_sync(struct hci_dev *hdev, void *data)
>         if (conn->sid == HCI_SID_INVALID) {
>                 err = __hci_cmd_sync_status_sk(hdev, HCI_OP_NOP, 0, NULL,
>                                                HCI_EV_LE_EXT_ADV_REPORT,
> -                                              conn->conn_timeout, NULL);
> +                                              HCI_CMD_TIMEOUT, NULL);
>                 if (err == -ETIMEDOUT)
>                         goto done;
>         }
> @@ -7187,7 +7187,7 @@ static int hci_le_pa_create_sync(struct hci_dev *hdev, void *data)
>         err = __hci_cmd_sync_status_sk(hdev, HCI_OP_LE_PA_CREATE_SYNC,
>                                        sizeof(cp), &cp,
>                                        HCI_EV_LE_PA_SYNC_ESTABLISHED,
> -                                      conn->conn_timeout, NULL);
> +                                      HCI_CMD_TIMEOUT, NULL);
>         if (err == -ETIMEDOUT)
>                 __hci_cmd_sync_status(hdev, HCI_OP_LE_PA_CREATE_SYNC_CANCEL,
>                                       0, NULL, HCI_CMD_TIMEOUT);
>
> ---
> base-commit: bdb9aba465a85122bcba01a6154e237b9843e25b
> change-id: 20260108-pa_sync_cmd_timeout-ff46f67b5d2a
>
> Best regards,
> --
> Yang Li <yang.li@amlogic.com>
>
>


-- 
Luiz Augusto von Dentz
Re: [PATCH] Bluetooth: hci_sync: use HCI_CMD_TIMEOUT for PA sync commands
Posted by Yang Li 1 month ago 
Hi Luiz
> [ EXTERNAL EMAIL ]
>
> Hi Yang,
>
> On Thu, Jan 8, 2026 at 1:03 AM Yang Li via B4 Relay
> <devnull+yang.li.amlogic.com@kernel.org> wrote:
>> From: Yang Li <yang.li@amlogic.com>
>>
>> PA sync HCI commands incorrectly use conn->conn_timeout, which defaults
>> to 20s and is too long. If the PA Sync Established event is not
>> received, the command remains pending and causes userspace timeouts.
> Im pretty sure this is impossible scenario with bluetooth-next, since
> 1. only one work can be running hci_le_pa_create_sync at time so
> HCI_EV_LE_PA_SYNC_ESTABLISHED cannot be outstanding 2. The
> conn->timeout shall be aligned with socket timeout so perhaps the
> problem is userspace is not setting the socket timeout correctly or
> something.


Well, I got it.

I noticed that BlueZ has a default setting for sync_time with the value 
BT_ISO_SYNC_TIMEOUT=0x07d0 /* 20 secs */.

I would like to know the rationale behind setting it to 20 seconds 
initially. This value seems a bit long to me. Can I directly change this 
value as:

BT_ISO_SYNC_TIMEOUT=0x00C8 /* 2 secs */

>> Signed-off-by: Yang Li <yang.li@amlogic.com>
>> ---
>>   net/bluetooth/hci_sync.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
>> index f04a90bce4a9..58292b01f062 100644
>> --- a/net/bluetooth/hci_sync.c
>> +++ b/net/bluetooth/hci_sync.c
>> @@ -7159,7 +7159,7 @@ static int hci_le_pa_create_sync(struct hci_dev *hdev, void *data)
>>          if (conn->sid == HCI_SID_INVALID) {
>>                  err = __hci_cmd_sync_status_sk(hdev, HCI_OP_NOP, 0, NULL,
>>                                                 HCI_EV_LE_EXT_ADV_REPORT,
>> -                                              conn->conn_timeout, NULL);
>> +                                              HCI_CMD_TIMEOUT, NULL);
>>                  if (err == -ETIMEDOUT)
>>                          goto done;
>>          }
>> @@ -7187,7 +7187,7 @@ static int hci_le_pa_create_sync(struct hci_dev *hdev, void *data)
>>          err = __hci_cmd_sync_status_sk(hdev, HCI_OP_LE_PA_CREATE_SYNC,
>>                                         sizeof(cp), &cp,
>>                                         HCI_EV_LE_PA_SYNC_ESTABLISHED,
>> -                                      conn->conn_timeout, NULL);
>> +                                      HCI_CMD_TIMEOUT, NULL);
>>          if (err == -ETIMEDOUT)
>>                  __hci_cmd_sync_status(hdev, HCI_OP_LE_PA_CREATE_SYNC_CANCEL,
>>                                        0, NULL, HCI_CMD_TIMEOUT);
>>
>> ---
>> base-commit: bdb9aba465a85122bcba01a6154e237b9843e25b
>> change-id: 20260108-pa_sync_cmd_timeout-ff46f67b5d2a
>>
>> Best regards,
>> --
>> Yang Li <yang.li@amlogic.com>
>>
>>
>
> --
> Luiz Augusto von Dentz

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