[PATCH v7 2/9] Bluetooth: Rework le_scan_restart for hci_sync

Brian Gix
2022-08-05T23:42:53Z

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@intel.com>
---
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 e22837510ab1..75e7c0a01ab1 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);

--
2.37.1