+Brian Gix
On Thu, Jun 15, 2023 at 10:27 AM Luiz Augusto von Dentz
<luiz.dentz@xxxxxxxxx> wrote:
>
> Hi Stefan,
>
> On Thu, Jun 15, 2023 at 5:06 AM Stefan Agner <stefan@xxxxxxxx> wrote:
> >
> > Hi Brian, hi all,
> >
> > We experienced quite some Bluetooth issues after moving from Linux 5.15
> > to 6.1 on Home Assistant OS, especially on Intel NUC type systems (which
> > is a popular choice in our community, so it might just be that). When
> > continuously scanning/listening for BLE packets, the packet flow
> > suddenly ends. Depending on which and how many devices (possibly also
> > other factors) within minutes or hours.
> >
> > Jan (in cc) was able to bisect the issue, and was able to pinpoint the
> > problem to this change.
> >
> > Meanwhile I was able to confirm, that reverting this single commit on
> > the latest 6.1.34 seems to resolve the issue.
> >
> > I've reviewed the change and surrounding code, and one thing I've
> > noticed is that the if statement to set cp.filter_dup in
> > hci_le_set_ext_scan_enable_sync and hci_le_set_scan_enable_sync are
> > different. Not sure if that needs to be the way it is, but my outside
> > gut feeling says hci_le_set_ext_scan_enable_sync should use "if (val &&
> > hci_dev_test_flag(hdev, HCI_MESH))" as well.
> >
> > However, that did not fix the problem (but maybe it is wrong
> > nonetheless?).
> >
> > Anyone has an idea what could be the problem here?
>
> Are there any logs of the problem? Does any HCI command fails or
> anything so that we can track down what could be wrong?
@Brian Gix perhaps you have a better idea what is going wrong here?
> > --
> > Stefan
> >
> > On 2022-07-27 15:58, Brian Gix wrote:
> > > le_scan_restart delayed work queue was running as a deprecated
> > > hci_request instead of on the newer thread-safe hci_sync mechanism.
> > >
> > > Signed-off-by: Brian Gix <brian.gix@xxxxxxxxx>
> > > ---
> > > net/bluetooth/hci_request.c | 89 -------------------------------------
> > > net/bluetooth/hci_sync.c | 75 +++++++++++++++++++++++++++++++
> > > 2 files changed, 75 insertions(+), 89 deletions(-)
> > >
> > > diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
> > > index 32fefaa0d3ca..114af7350363 100644
> > > --- a/net/bluetooth/hci_request.c
> > > +++ b/net/bluetooth/hci_request.c
> > > @@ -1975,92 +1975,6 @@ int hci_abort_conn(struct hci_conn *conn, u8 reason)
> > > return 0;
> > > }
> > >
> > > -static int le_scan_restart(struct hci_request *req, unsigned long opt)
> > > -{
> > > - struct hci_dev *hdev = req->hdev;
> > > -
> > > - /* If controller is not scanning we are done. */
> > > - if (!hci_dev_test_flag(hdev, HCI_LE_SCAN))
> > > - return 0;
> > > -
> > > - if (hdev->scanning_paused) {
> > > - bt_dev_dbg(hdev, "Scanning is paused for suspend");
> > > - return 0;
> > > - }
> > > -
> > > - hci_req_add_le_scan_disable(req, false);
> > > -
> > > - if (use_ext_scan(hdev)) {
> > > - struct hci_cp_le_set_ext_scan_enable ext_enable_cp;
> > > -
> > > - memset(&ext_enable_cp, 0, sizeof(ext_enable_cp));
> > > - ext_enable_cp.enable = LE_SCAN_ENABLE;
> > > - ext_enable_cp.filter_dup = LE_SCAN_FILTER_DUP_ENABLE;
> > > -
> > > - hci_req_add(req, HCI_OP_LE_SET_EXT_SCAN_ENABLE,
> > > - sizeof(ext_enable_cp), &ext_enable_cp);
> > > - } else {
> > > - struct hci_cp_le_set_scan_enable cp;
> > > -
> > > - memset(&cp, 0, sizeof(cp));
> > > - cp.enable = LE_SCAN_ENABLE;
> > > - cp.filter_dup = LE_SCAN_FILTER_DUP_ENABLE;
> > > - hci_req_add(req, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp);
> > > - }
> > > -
> > > - return 0;
> > > -}
> > > -
> > > -static void le_scan_restart_work(struct work_struct *work)
> > > -{
> > > - struct hci_dev *hdev = container_of(work, struct hci_dev,
> > > - le_scan_restart.work);
> > > - unsigned long timeout, duration, scan_start, now;
> > > - u8 status;
> > > -
> > > - bt_dev_dbg(hdev, "");
> > > -
> > > - hci_req_sync(hdev, le_scan_restart, 0, HCI_CMD_TIMEOUT, &status);
> > > - if (status) {
> > > - bt_dev_err(hdev, "failed to restart LE scan: status %d",
> > > - status);
> > > - return;
> > > - }
> > > -
> > > - hci_dev_lock(hdev);
> > > -
> > > - if (!test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER, &hdev->quirks) ||
> > > - !hdev->discovery.scan_start)
> > > - goto unlock;
> > > -
> > > - /* When the scan was started, hdev->le_scan_disable has been queued
> > > - * after duration from scan_start. During scan restart this job
> > > - * has been canceled, and we need to queue it again after proper
> > > - * timeout, to make sure that scan does not run indefinitely.
> > > - */
> > > - duration = hdev->discovery.scan_duration;
> > > - scan_start = hdev->discovery.scan_start;
> > > - now = jiffies;
> > > - if (now - scan_start <= duration) {
> > > - int elapsed;
> > > -
> > > - if (now >= scan_start)
> > > - elapsed = now - scan_start;
> > > - else
> > > - elapsed = ULONG_MAX - scan_start + now;
> > > -
> > > - timeout = duration - elapsed;
> > > - } else {
> > > - timeout = 0;
> > > - }
> > > -
> > > - queue_delayed_work(hdev->req_workqueue,
> > > - &hdev->le_scan_disable, timeout);
> > > -
> > > -unlock:
> > > - hci_dev_unlock(hdev);
> > > -}
> > > -
> > > bool hci_req_stop_discovery(struct hci_request *req)
> > > {
> > > struct hci_dev *hdev = req->hdev;
> > > @@ -2158,7 +2072,6 @@ int hci_req_configure_datapath(struct hci_dev
> > > *hdev, struct bt_codec *codec)
> > >
> > > void hci_request_setup(struct hci_dev *hdev)
> > > {
> > > - INIT_DELAYED_WORK(&hdev->le_scan_restart, le_scan_restart_work);
> > > INIT_DELAYED_WORK(&hdev->adv_instance_expire, adv_timeout_expire);
> > > INIT_DELAYED_WORK(&hdev->interleave_scan, interleave_scan_work);
> > > }
> > > @@ -2167,8 +2080,6 @@ void hci_request_cancel_all(struct hci_dev *hdev)
> > > {
> > > __hci_cmd_sync_cancel(hdev, ENODEV);
> > >
> > > - cancel_delayed_work_sync(&hdev->le_scan_restart);
> > > -
> > > if (hdev->adv_instance_timeout) {
> > > cancel_delayed_work_sync(&hdev->adv_instance_expire);
> > > hdev->adv_instance_timeout = 0;
> > > diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
> > > index 7dae2ee1bb82..19d57ec0feb8 100644
> > > --- a/net/bluetooth/hci_sync.c
> > > +++ b/net/bluetooth/hci_sync.c
> > > @@ -392,6 +392,79 @@ static void le_scan_disable(struct work_struct *work)
> > > hci_dev_unlock(hdev);
> > > }
> > >
> > > +static int hci_le_set_scan_enable_sync(struct hci_dev *hdev, u8 val,
> > > + u8 filter_dup);
> > > +static int hci_le_scan_restart_sync(struct hci_dev *hdev)
> > > +{
> > > + /* If controller is not scanning we are done. */
> > > + if (!hci_dev_test_flag(hdev, HCI_LE_SCAN))
> > > + return 0;
> > > +
> > > + if (hdev->scanning_paused) {
> > > + bt_dev_dbg(hdev, "Scanning is paused for suspend");
> > > + return 0;
> > > + }
> > > +
> > > + hci_le_set_scan_enable_sync(hdev, LE_SCAN_DISABLE, 0x00);
> > > + return hci_le_set_scan_enable_sync(hdev, LE_SCAN_ENABLE,
> > > + LE_SCAN_FILTER_DUP_ENABLE);
> > > +}
> > > +
> > > +static int le_scan_restart_sync(struct hci_dev *hdev, void *data)
> > > +{
> > > + return hci_le_scan_restart_sync(hdev);
> > > +}
> > > +
> > > +static void le_scan_restart(struct work_struct *work)
> > > +{
> > > + struct hci_dev *hdev = container_of(work, struct hci_dev,
> > > + le_scan_restart.work);
> > > + unsigned long timeout, duration, scan_start, now;
> > > + int status;
> > > +
> > > + bt_dev_dbg(hdev, "");
> > > +
> > > + hci_dev_lock(hdev);
> > > +
> > > + status = hci_cmd_sync_queue(hdev, le_scan_restart_sync, NULL, NULL);
> > > + if (status) {
> > > + bt_dev_err(hdev, "failed to restart LE scan: status %d",
> > > + status);
> > > + goto unlock;
> > > + }
> > > +
> > > + if (!test_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER, &hdev->quirks) ||
> > > + !hdev->discovery.scan_start)
> > > + goto unlock;
> > > +
> > > + /* When the scan was started, hdev->le_scan_disable has been queued
> > > + * after duration from scan_start. During scan restart this job
> > > + * has been canceled, and we need to queue it again after proper
> > > + * timeout, to make sure that scan does not run indefinitely.
> > > + */
> > > + duration = hdev->discovery.scan_duration;
> > > + scan_start = hdev->discovery.scan_start;
> > > + now = jiffies;
> > > + if (now - scan_start <= duration) {
> > > + int elapsed;
> > > +
> > > + if (now >= scan_start)
> > > + elapsed = now - scan_start;
> > > + else
> > > + elapsed = ULONG_MAX - scan_start + now;
> > > +
> > > + timeout = duration - elapsed;
> > > + } else {
> > > + timeout = 0;
> > > + }
> > > +
> > > + queue_delayed_work(hdev->req_workqueue,
> > > + &hdev->le_scan_disable, timeout);
> > > +
> > > +unlock:
> > > + hci_dev_unlock(hdev);
> > > +}
> > > +
> > > void hci_cmd_sync_init(struct hci_dev *hdev)
> > > {
> > > INIT_WORK(&hdev->cmd_sync_work, hci_cmd_sync_work);
> > > @@ -400,6 +473,7 @@ void hci_cmd_sync_init(struct hci_dev *hdev)
> > >
> > > INIT_WORK(&hdev->cmd_sync_cancel_work, hci_cmd_sync_cancel_work);
> > > INIT_DELAYED_WORK(&hdev->le_scan_disable, le_scan_disable);
> > > + INIT_DELAYED_WORK(&hdev->le_scan_restart, le_scan_restart);
> > > }
> > >
> > > void hci_cmd_sync_clear(struct hci_dev *hdev)
> > > @@ -4488,6 +4562,7 @@ int hci_dev_close_sync(struct hci_dev *hdev)
> > > cancel_delayed_work(&hdev->power_off);
> > > cancel_delayed_work(&hdev->ncmd_timer);
> > > cancel_delayed_work(&hdev->le_scan_disable);
> > > + cancel_delayed_work(&hdev->le_scan_restart);
> > >
> > > hci_request_cancel_all(hdev);
>
>
>
> --
> Luiz Augusto von Dentz
--
Luiz Augusto von Dentz
