Re: [PATCH v2 2/2] Bluetooth: Fix stop discovery while in STARTING state

[Gustavo Padovan <gustavo@padovan.org>]

Hi Jaganath,

* Jaganath Kanakkassery <jaganath.k@samsung.com> [2013-01-04 13:16:11 +0530]:

> Hi Gustavo,
> 
> --------------------------------------------------
> From: "Gustavo Padovan" <gustavo@padovan.org>
> Sent: Friday, January 04, 2013 1:08 AM
> To: "Jaganath Kanakkassery" <jaganath.k@samsung.com>
> Cc: <linux-bluetooth@vger.kernel.org>
> Subject: Re: [PATCH v2 2/2] Bluetooth: Fix stop discovery while in
> STARTING state
> 
> >Hi Jaganath,
> >
> >* Jaganath Kanakkassery <jaganath.k@samsung.com> [2012-12-21
> >18:20:25 +0530]:
> >
> >>If stop_discovery() is called when discovery state is STARTING, it
> >>will be failed currently. This patch fixes this.
> >>
> >>Signed-off-by: Jaganath Kanakkassery <jaganath.k@samsung.com>
> >>---
> >> include/net/bluetooth/hci_core.h |    2 ++
> >> net/bluetooth/hci_event.c        |   14 ++++++++++++--
> >> net/bluetooth/mgmt.c             |   31 ++++++++++++++++++++++++++++++-
> >> 3 files changed, 44 insertions(+), 3 deletions(-)
> >>
> >>diff --git a/include/net/bluetooth/hci_core.h
> >>b/include/net/bluetooth/hci_core.h
> >>index 119fcb6..c2886b7 100644
> >>--- a/include/net/bluetooth/hci_core.h
> >>+++ b/include/net/bluetooth/hci_core.h
> >>@@ -64,6 +64,7 @@ struct discovery_state {
> >> DISCOVERY_RESOLVING,
> >> DISCOVERY_STOPPING,
> >> } state;
> >>+ u8  discovering;
> >> struct list_head all; /* All devices found during inquiry */
> >> struct list_head unknown; /* Name state not known */
> >> struct list_head resolve; /* Name needs to be resolved */
> >>@@ -1066,6 +1067,7 @@ int mgmt_device_found(struct hci_dev
> >>*hdev, bdaddr_t *bdaddr, u8 link_type,
> >> int mgmt_remote_name(struct hci_dev *hdev, bdaddr_t *bdaddr, u8
> >>link_type,
> >>      u8 addr_type, s8 rssi, u8 *name, u8 name_len);
> >> int mgmt_start_discovery_failed(struct hci_dev *hdev, u8 status);
> >>+int mgmt_start_discovery_complete(struct hci_dev *hdev, u8 status);
> >> int mgmt_stop_discovery_failed(struct hci_dev *hdev, u8 status);
> >> int mgmt_discovering(struct hci_dev *hdev, u8 discovering);
> >> int mgmt_interleaved_discovery(struct hci_dev *hdev);
> >>diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> >>index e248e7c..b486458 100644
> >>--- a/net/bluetooth/hci_event.c
> >>+++ b/net/bluetooth/hci_event.c
> >>@@ -1092,7 +1092,12 @@ static void
> >>hci_cc_le_set_scan_enable(struct hci_dev *hdev,
> >> set_bit(HCI_LE_SCAN, &hdev->dev_flags);
> >>
> >> hci_dev_lock(hdev);
> >>- hci_discovery_set_state(hdev, DISCOVERY_FINDING);
> >>+ if (hdev->discovery.state == DISCOVERY_STOPPING) {
> >>+ hci_cancel_le_scan(hdev);
> >>+ mgmt_start_discovery_complete(hdev, 0);
> >
> >Reply to mgmt with an error here might be better.
> 
> I think the best error which can be given here is
> MGMT_STATUS_CANCELLED. But this error is not accessible in hci_event.c
> 
> >>+ } else {
> >>+ hci_discovery_set_state(hdev, DISCOVERY_FINDING);
> >>+ }
> >> hci_dev_unlock(hdev);
> >> break;
> >>
> >>@@ -1189,7 +1194,12 @@ static void hci_cs_inquiry(struct hci_dev
> >>*hdev, __u8 status)
> >> set_bit(HCI_INQUIRY, &hdev->flags);
> >>
> >> hci_dev_lock(hdev);
> >>- hci_discovery_set_state(hdev, DISCOVERY_FINDING);
> >>+ if (hdev->discovery.state == DISCOVERY_STOPPING) {
> >>+ hci_cancel_inquiry(hdev);
> >>+ mgmt_start_discovery_complete(hdev, 0);
> >>+ } else {
> >>+ hci_discovery_set_state(hdev, DISCOVERY_FINDING);
> >>+ }
> >> hci_dev_unlock(hdev);
> >> }
> >>
> >>diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
> >>index d6c0d78..ba4171f 100644
> >>--- a/net/bluetooth/mgmt.c
> >>+++ b/net/bluetooth/mgmt.c
> >>@@ -2385,7 +2385,8 @@ static int stop_discovery(struct sock *sk,
> >>struct hci_dev *hdev, void *data,
> >>
> >> hci_dev_lock(hdev);
> >>
> >>- if (!hci_discovery_active(hdev)) {
> >>+ if (hdev->discovery.state != DISCOVERY_STARTING &&
> >>+     !hci_discovery_active(hdev)) {
> >> err = cmd_complete(sk, hdev->id, MGMT_OP_STOP_DISCOVERY,
> >>    MGMT_STATUS_REJECTED, &mgmt_cp->type,
> >>    sizeof(mgmt_cp->type));
> >>@@ -2433,6 +2434,10 @@ static int stop_discovery(struct sock
> >>*sk, struct hci_dev *hdev, void *data,
> >>
> >> break;
> >>
> >>+ case DISCOVERY_STARTING:
> >>+ err = 0;
> >>+ break;
> >>+
> >> default:
> >> BT_DBG("unknown discovery state %u", hdev->discovery.state);
> >> err = -EFAULT;
> >>@@ -3624,6 +3629,25 @@ int mgmt_start_discovery_failed(struct
> >>hci_dev *hdev, u8 status)
> >> return err;
> >> }
> >>
> >>+int mgmt_start_discovery_complete(struct hci_dev *hdev, u8 status)
> >>+{
> >>+ struct pending_cmd *cmd;
> >>+ u8 type;
> >>+ int err;
> >>+
> >>+ cmd = mgmt_pending_find(MGMT_OP_START_DISCOVERY, hdev);
> >>+ if (!cmd)
> >>+ return -ENOENT;
> >>+
> >>+ type = hdev->discovery.type;
> >>+
> >>+ err = cmd_complete(cmd->sk, hdev->id, cmd->opcode, mgmt_status(status),
> >>+    &type, sizeof(type));
> >>+ mgmt_pending_remove(cmd);
> >>+
> >>+ return err;
> >>+}
> >
> >This is exactly the same thing as mgmt_start_discovery_failed(),
> >just rename it
> >to _complete() as you did with mgmt_stop_discovery_failed(). Do it as a
> >separate patch.
> 
> mgmt_start_discovery_failed() sets discovery state to STOPPED which
> also sends
> stop_discovery_complete internally. I think both are inappropriate
> at the point
> where mgmt_start_discovery_complete() is called.
> 
> How abt renaming the new function mgmt_start_discovery_complete() to
> mgmt_start_discovery_cancelled and send MGMT_STATUS_CANCELLED in that?

Ok, go with this approach.

	Gustavo