[PATCH v2 0/2] LE support for MGMT Stop Discovery

[PATCH v2 0/2] LE support for MGMT Stop Discovery

[Andre Guedes]

>From the previous cover letter:

This small patch series adds LE support for Stop Discovery MGMT command.
Now, we are able to stop LE discovery procedues (LE-only and interleaved).

A brief word about patch 1/2: due to discovery state machine, we don't need
to worry about canceling hdev->le_scan work since it is never pending or
running when hci_cancel_le_scan is called.

Andre Guedes (2):
  Bluetooth: Add hci_cancel_le_scan() to hci_core
  Bluetooth: LE support for MGMT stop discovery

 include/net/bluetooth/hci_core.h |    1 +
 net/bluetooth/hci_core.c         |   21 +++++++++++++++++++++
 net/bluetooth/hci_event.c        |    6 +++++-
 net/bluetooth/mgmt.c             |    6 +++++-
 4 files changed, 32 insertions(+), 2 deletions(-)

-- 
1.7.9.3

[PATCH v2 1/2] Bluetooth: Add hci_cancel_le_scan() to hci_core

[Andre Guedes]

This patch adds to hci_core the hci_cancel_le_scan function which
should be used to cancel an ongoing LE scan.

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 include/net/bluetooth/hci_core.h |    1 +
 net/bluetooth/hci_core.c         |   21 +++++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index daefaac..87bca3e 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -1071,5 +1071,6 @@ int hci_do_inquiry(struct hci_dev *hdev, u8 length);
 int hci_cancel_inquiry(struct hci_dev *hdev);
 int hci_le_scan(struct hci_dev *hdev, u8 type, u16 interval, u16 window,
 		int timeout);
+int hci_cancel_le_scan(struct hci_dev *hdev);
 
 #endif /* __HCI_CORE_H */
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
index 59ec99e..0320a02 100644
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1667,6 +1667,27 @@ static int hci_do_le_scan(struct hci_dev *hdev, u8 type, u16 interval,
 	return 0;
 }
 
+int hci_cancel_le_scan(struct hci_dev *hdev)
+{
+	bool canceled;
+
+	BT_DBG("%s", hdev->name);
+
+	if (!test_bit(HCI_LE_SCAN, &hdev->dev_flags))
+		return -EALREADY;
+
+	canceled = cancel_delayed_work(&hdev->le_scan_disable);
+	if (canceled) {
+		struct hci_cp_le_set_scan_enable cp;
+
+		/* Send HCI command to disable LE Scan */
+		memset(&cp, 0, sizeof(cp));
+		hci_send_cmd(hdev, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp);
+	}
+
+	return 0;
+}
+
 static void le_scan_disable_work(struct work_struct *work)
 {
 	struct hci_dev *hdev = container_of(work, struct hci_dev,
-- 
1.7.9.3

[PATCH v2 2/2] Bluetooth: LE support for MGMT stop discovery

[Andre Guedes]

This patch adds LE support to MGMT stop discovery command. So,
now we are able to cancel LE discovery procedures (LE-only and
interleaved).

Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
---
 net/bluetooth/hci_event.c |    6 +++++-
 net/bluetooth/mgmt.c      |    6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index badb785..b896447 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -1092,8 +1092,12 @@ static void hci_cc_le_set_scan_enable(struct hci_dev *hdev,
 		break;
 
 	case LE_SCANNING_DISABLED:
-		if (status)
+		if (status) {
+			hci_dev_lock(hdev);
+			mgmt_stop_discovery_failed(hdev, status);
+			hci_dev_unlock(hdev);
 			return;
+		}
 
 		clear_bit(HCI_LE_SCAN, &hdev->dev_flags);
 
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index 7fcff88..ad4eba0 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -2382,7 +2382,11 @@ static int stop_discovery(struct sock *sk, struct hci_dev *hdev, void *data,
 	}
 
 	if (hdev->discovery.state == DISCOVERY_FINDING) {
-		err = hci_cancel_inquiry(hdev);
+		if (test_bit(HCI_INQUIRY, &hdev->flags))
+			err = hci_cancel_inquiry(hdev);
+		else
+			err = hci_cancel_le_scan(hdev);
+
 		if (err < 0)
 			mgmt_pending_remove(cmd);
 		else
-- 
1.7.9.3

Re: [PATCH v2 1/2] Bluetooth: Add hci_cancel_le_scan() to hci_core

[Marcel Holtmann]

Hi Andre,

> This patch adds to hci_core the hci_cancel_le_scan function which
> should be used to cancel an ongoing LE scan.
> 
> Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
> ---
>  include/net/bluetooth/hci_core.h |    1 +
>  net/bluetooth/hci_core.c         |   21 +++++++++++++++++++++
>  2 files changed, 22 insertions(+)
> 
> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> index daefaac..87bca3e 100644
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -1071,5 +1071,6 @@ int hci_do_inquiry(struct hci_dev *hdev, u8 length);
>  int hci_cancel_inquiry(struct hci_dev *hdev);
>  int hci_le_scan(struct hci_dev *hdev, u8 type, u16 interval, u16 window,
>  		int timeout);
> +int hci_cancel_le_scan(struct hci_dev *hdev);
>  
>  #endif /* __HCI_CORE_H */
> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> index 59ec99e..0320a02 100644
> --- a/net/bluetooth/hci_core.c
> +++ b/net/bluetooth/hci_core.c
> @@ -1667,6 +1667,27 @@ static int hci_do_le_scan(struct hci_dev *hdev, u8 type, u16 interval,
>  	return 0;
>  }
>  
> +int hci_cancel_le_scan(struct hci_dev *hdev)
> +{
> +	bool canceled;
> +
> +	BT_DBG("%s", hdev->name);
> +
> +	if (!test_bit(HCI_LE_SCAN, &hdev->dev_flags))
> +		return -EALREADY;
> +
> +	canceled = cancel_delayed_work(&hdev->le_scan_disable);

why are we using the canceled variable here? Seems pointless.

> +	if (canceled) {
> +		struct hci_cp_le_set_scan_enable cp;
> +
> +		/* Send HCI command to disable LE Scan */
> +		memset(&cp, 0, sizeof(cp));
> +		hci_send_cmd(hdev, HCI_OP_LE_SET_SCAN_ENABLE, sizeof(cp), &cp);
> +	}
> +
> +	return 0;
> +}
> +

Regards

Marcel

Re: [PATCH v2 2/2] Bluetooth: LE support for MGMT stop discovery

[Marcel Holtmann]

Hi Andre,

> This patch adds LE support to MGMT stop discovery command. So,
> now we are able to cancel LE discovery procedures (LE-only and
> interleaved).
> 
> Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
> ---
>  net/bluetooth/hci_event.c |    6 +++++-
>  net/bluetooth/mgmt.c      |    6 +++++-
>  2 files changed, 10 insertions(+), 2 deletions(-)

Acked-by: Marcel Holtmann <marcel@holtmann.org>

Regards

Marcel

Re: [PATCH v2 1/2] Bluetooth: Add hci_cancel_le_scan() to hci_core

[Andre Guedes]

Hi Marcel,

On Thu, Mar 15, 2012 at 12:26 PM, Marcel Holtmann <marcel@holtmann.org> wro=
te:
> Hi Andre,
>
>> This patch adds to hci_core the hci_cancel_le_scan function which
>> should be used to cancel an ongoing LE scan.
>>
>> Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
>> ---
>> =A0include/net/bluetooth/hci_core.h | =A0 =A01 +
>> =A0net/bluetooth/hci_core.c =A0 =A0 =A0 =A0 | =A0 21 +++++++++++++++++++=
++
>> =A02 files changed, 22 insertions(+)
>>
>> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hc=
i_core.h
>> index daefaac..87bca3e 100644
>> --- a/include/net/bluetooth/hci_core.h
>> +++ b/include/net/bluetooth/hci_core.h
>> @@ -1071,5 +1071,6 @@ int hci_do_inquiry(struct hci_dev *hdev, u8 length=
);
>> =A0int hci_cancel_inquiry(struct hci_dev *hdev);
>> =A0int hci_le_scan(struct hci_dev *hdev, u8 type, u16 interval, u16 wind=
ow,
>> =A0 =A0 =A0 =A0 =A0 =A0 =A0 int timeout);
>> +int hci_cancel_le_scan(struct hci_dev *hdev);
>>
>> =A0#endif /* __HCI_CORE_H */
>> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
>> index 59ec99e..0320a02 100644
>> --- a/net/bluetooth/hci_core.c
>> +++ b/net/bluetooth/hci_core.c
>> @@ -1667,6 +1667,27 @@ static int hci_do_le_scan(struct hci_dev *hdev, u=
8 type, u16 interval,
>> =A0 =A0 =A0 return 0;
>> =A0}
>>
>> +int hci_cancel_le_scan(struct hci_dev *hdev)
>> +{
>> + =A0 =A0 bool canceled;
>> +
>> + =A0 =A0 BT_DBG("%s", hdev->name);
>> +
>> + =A0 =A0 if (!test_bit(HCI_LE_SCAN, &hdev->dev_flags))
>> + =A0 =A0 =A0 =A0 =A0 =A0 return -EALREADY;
>> +
>> + =A0 =A0 canceled =3D cancel_delayed_work(&hdev->le_scan_disable);
>
> why are we using the canceled variable here? Seems pointless.

Because le_scan_disable work may be running when cancel_delayed_work
returns (canceled =3D=3D 0). If le_scan_disable work is running, we should
not send HCI_OP_LE_SET_SCAN_ENABLE command since le_scan_disable work
already sends it.

This way we avoid sending two HCI_OP_LE_SET_SCAN_ENABLE commands when
this race condition occurs.

BR,

Andre

Re: [PATCH v2 1/2] Bluetooth: Add hci_cancel_le_scan() to hci_core

[Marcel Holtmann]

Hi Andre,

> >> This patch adds to hci_core the hci_cancel_le_scan function which
> >> should be used to cancel an ongoing LE scan.
> >>
> >> Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
> >> ---
> >>  include/net/bluetooth/hci_core.h |    1 +
> >>  net/bluetooth/hci_core.c         |   21 +++++++++++++++++++++
> >>  2 files changed, 22 insertions(+)
> >>
> >> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> >> index daefaac..87bca3e 100644
> >> --- a/include/net/bluetooth/hci_core.h
> >> +++ b/include/net/bluetooth/hci_core.h
> >> @@ -1071,5 +1071,6 @@ int hci_do_inquiry(struct hci_dev *hdev, u8 length);
> >>  int hci_cancel_inquiry(struct hci_dev *hdev);
> >>  int hci_le_scan(struct hci_dev *hdev, u8 type, u16 interval, u16 window,
> >>               int timeout);
> >> +int hci_cancel_le_scan(struct hci_dev *hdev);
> >>
> >>  #endif /* __HCI_CORE_H */
> >> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
> >> index 59ec99e..0320a02 100644
> >> --- a/net/bluetooth/hci_core.c
> >> +++ b/net/bluetooth/hci_core.c
> >> @@ -1667,6 +1667,27 @@ static int hci_do_le_scan(struct hci_dev *hdev, u8 type, u16 interval,
> >>       return 0;
> >>  }
> >>
> >> +int hci_cancel_le_scan(struct hci_dev *hdev)
> >> +{
> >> +     bool canceled;
> >> +
> >> +     BT_DBG("%s", hdev->name);
> >> +
> >> +     if (!test_bit(HCI_LE_SCAN, &hdev->dev_flags))
> >> +             return -EALREADY;
> >> +
> >> +     canceled = cancel_delayed_work(&hdev->le_scan_disable);
> >
> > why are we using the canceled variable here? Seems pointless.
> 
> Because le_scan_disable work may be running when cancel_delayed_work
> returns (canceled == 0). If le_scan_disable work is running, we should
> not send HCI_OP_LE_SET_SCAN_ENABLE command since le_scan_disable work
> already sends it.

I got that part, but I meant why using an extra variable here?

	if (cancel_delayed_work(&hdev->le_scan_disable)) {

		...

	}

This is as clean and does exactly the same job. Or do I miss something
here?

Regards

Marcel

Re: [PATCH v2 1/2] Bluetooth: Add hci_cancel_le_scan() to hci_core

[Andre Guedes]

Hi Marcel,

On Thu, Mar 15, 2012 at 3:36 PM, Marcel Holtmann <marcel@holtmann.org> wrot=
e:
> Hi Andre,
>
>> >> This patch adds to hci_core the hci_cancel_le_scan function which
>> >> should be used to cancel an ongoing LE scan.
>> >>
>> >> Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
>> >> ---
>> >> =A0include/net/bluetooth/hci_core.h | =A0 =A01 +
>> >> =A0net/bluetooth/hci_core.c =A0 =A0 =A0 =A0 | =A0 21 ++++++++++++++++=
+++++
>> >> =A02 files changed, 22 insertions(+)
>> >>
>> >> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth=
/hci_core.h
>> >> index daefaac..87bca3e 100644
>> >> --- a/include/net/bluetooth/hci_core.h
>> >> +++ b/include/net/bluetooth/hci_core.h
>> >> @@ -1071,5 +1071,6 @@ int hci_do_inquiry(struct hci_dev *hdev, u8 len=
gth);
>> >> =A0int hci_cancel_inquiry(struct hci_dev *hdev);
>> >> =A0int hci_le_scan(struct hci_dev *hdev, u8 type, u16 interval, u16 w=
indow,
>> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 int timeout);
>> >> +int hci_cancel_le_scan(struct hci_dev *hdev);
>> >>
>> >> =A0#endif /* __HCI_CORE_H */
>> >> diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
>> >> index 59ec99e..0320a02 100644
>> >> --- a/net/bluetooth/hci_core.c
>> >> +++ b/net/bluetooth/hci_core.c
>> >> @@ -1667,6 +1667,27 @@ static int hci_do_le_scan(struct hci_dev *hdev=
, u8 type, u16 interval,
>> >> =A0 =A0 =A0 return 0;
>> >> =A0}
>> >>
>> >> +int hci_cancel_le_scan(struct hci_dev *hdev)
>> >> +{
>> >> + =A0 =A0 bool canceled;
>> >> +
>> >> + =A0 =A0 BT_DBG("%s", hdev->name);
>> >> +
>> >> + =A0 =A0 if (!test_bit(HCI_LE_SCAN, &hdev->dev_flags))
>> >> + =A0 =A0 =A0 =A0 =A0 =A0 return -EALREADY;
>> >> +
>> >> + =A0 =A0 canceled =3D cancel_delayed_work(&hdev->le_scan_disable);
>> >
>> > why are we using the canceled variable here? Seems pointless.
>>
>> Because le_scan_disable work may be running when cancel_delayed_work
>> returns (canceled =3D=3D 0). If le_scan_disable work is running, we shou=
ld
>> not send HCI_OP_LE_SET_SCAN_ENABLE command since le_scan_disable work
>> already sends it.
>
> I got that part, but I meant why using an extra variable here?
>
> =A0 =A0 =A0 =A0if (cancel_delayed_work(&hdev->le_scan_disable)) {
>
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0...
>
> =A0 =A0 =A0 =A0}

Oh, sorry, now I see your point.

> This is as clean and does exactly the same job. Or do I miss something
> here?

You're right, I'll remove the variable and send a new version.

Thanks,

Andre