diff mbox series

[1/2] Bluetooth: Disable AdvMonitor SamplingPeriod while active scan

Message ID 20220803132319.1.I5acde3b5af78dbd2ea078d5eb4158d23b496ac87@changeid (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
Headers show
Series [1/2] Bluetooth: Disable AdvMonitor SamplingPeriod while active scan | expand

Checks

Context Check Description
netdev/tree_selection success Guessed tree name to be net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cover_letter success Single patches do not need cover letters
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 28 this patch: 28
netdev/cc_maintainers success CCed 9 of 9 maintainers
netdev/build_clang success Errors and warnings before: 10 this patch: 10
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 25 this patch: 25
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 119 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Manish Mandlik Aug. 3, 2022, 8:24 p.m. UTC 
Some controllers apply Sampling Period even while active scanning.
So, to keep the behavior consistent across all controllers, don't
use Sampling Period during active scanning to force the controller
to report all advertisements even if it matches the monitor.

Signed-off-by: Manish Mandlik <mmandlik@google.com>
Reviewed-by: Miao-chen Chou <mcchou@google.com>
---

 net/bluetooth/hci_sync.c |  6 ++++++
 net/bluetooth/msft.c     | 45 +++++++++++++++++++++++++++++++++++++---
 net/bluetooth/msft.h     |  2 ++
 3 files changed, 50 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index e6d804b82b67..cb0c219ebe1c 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -4649,6 +4649,9 @@  int hci_stop_discovery_sync(struct hci_dev *hdev)
 	if (use_ll_privacy(hdev))
 		hci_resume_advertising_sync(hdev);
 
+	/* Sampling Period is disabled while active scanning, re-enable it */
+	msft_set_active_scan(hdev, false);
+
 	/* No further actions needed for LE-only discovery */
 	if (d->type == DISCOV_TYPE_LE)
 		return 0;
@@ -5139,6 +5142,9 @@  int hci_start_discovery_sync(struct hci_dev *hdev)
 	if (err)
 		return err;
 
+	/* Disable Sampling Period while active scanning */
+	msft_set_active_scan(hdev, true);
+
 	bt_dev_dbg(hdev, "timeout %u ms", jiffies_to_msecs(timeout));
 
 	/* When service discovery is used and the controller has a
diff --git a/net/bluetooth/msft.c b/net/bluetooth/msft.c
index bee6a4c656be..f63c911b210c 100644
--- a/net/bluetooth/msft.c
+++ b/net/bluetooth/msft.c
@@ -101,6 +101,7 @@  struct msft_data {
 	struct list_head handle_map;
 	__u8 resuming;
 	__u8 suspending;
+	__u8 active_scan;
 	__u8 filter_enabled;
 };
 
@@ -333,14 +334,14 @@  static int msft_remove_monitor_sync(struct hci_dev *hdev,
 }
 
 /* This function requires the caller holds hci_req_sync_lock */
-int msft_suspend_sync(struct hci_dev *hdev)
+static void remove_all_monitors(struct hci_dev *hdev)
 {
 	struct msft_data *msft = hdev->msft_data;
 	struct adv_monitor *monitor;
 	int handle = 0;
 
 	if (!msft || !msft_monitor_supported(hdev))
-		return 0;
+		return;
 
 	msft->suspending = true;
 
@@ -356,6 +357,12 @@  int msft_suspend_sync(struct hci_dev *hdev)
 
 	/* All monitors have been removed */
 	msft->suspending = false;
+}
+
+/* This function requires the caller holds hci_req_sync_lock */
+int msft_suspend_sync(struct hci_dev *hdev)
+{
+	remove_all_monitors(hdev);
 
 	return 0;
 }
@@ -392,6 +399,7 @@  static bool msft_monitor_pattern_valid(struct adv_monitor *monitor)
 static int msft_add_monitor_sync(struct hci_dev *hdev,
 				 struct adv_monitor *monitor)
 {
+	struct msft_data *msft = hdev->msft_data;
 	struct msft_cp_le_monitor_advertisement *cp;
 	struct msft_le_monitor_advertisement_pattern_data *pattern_data;
 	struct msft_le_monitor_advertisement_pattern *pattern;
@@ -417,7 +425,16 @@  static int msft_add_monitor_sync(struct hci_dev *hdev,
 	cp->rssi_high = monitor->rssi.high_threshold;
 	cp->rssi_low = monitor->rssi.low_threshold;
 	cp->rssi_low_interval = (u8)monitor->rssi.low_threshold_timeout;
-	cp->rssi_sampling_period = monitor->rssi.sampling_period;
+
+	/* Some controllers apply Sampling Period even while active scanning.
+	 * So, to keep the behavior consistent across all controllers, don't
+	 * use Sampling Period during active scanning to force the controller
+	 * to report all advertisements even if it matches the monitor.
+	 */
+	if (msft->active_scan)
+		cp->rssi_sampling_period = 0;
+	else
+		cp->rssi_sampling_period = monitor->rssi.sampling_period;
 
 	cp->cond_type = MSFT_MONITOR_ADVERTISEMENT_TYPE_PATTERN;
 
@@ -815,6 +832,28 @@  void msft_req_add_set_filter_enable(struct hci_request *req, bool enable)
 	hci_req_add(req, hdev->msft_opcode, sizeof(cp), &cp);
 }
 
+/* This function requires the caller holds hci_req_sync_lock */
+void msft_set_active_scan(struct hci_dev *hdev, bool enable)
+{
+	struct msft_data *msft = hdev->msft_data;
+
+	if (!msft)
+		return;
+
+	/* Remove all monitors */
+	remove_all_monitors(hdev);
+
+	/* Clear all tracked devices */
+	hci_dev_lock(hdev);
+	hdev->advmon_pend_notify = false;
+	msft_monitor_device_del(hdev, 0, NULL, 0, true);
+	hci_dev_unlock(hdev);
+
+	/* Update active scan and reregister all monitors */
+	msft->active_scan = enable;
+	reregister_monitor(hdev);
+}
+
 int msft_set_filter_enable(struct hci_dev *hdev, bool enable)
 {
 	struct hci_request req;
diff --git a/net/bluetooth/msft.h b/net/bluetooth/msft.h
index 2a63205b377b..7dfd866dacc4 100644
--- a/net/bluetooth/msft.h
+++ b/net/bluetooth/msft.h
@@ -22,6 +22,7 @@  __u64 msft_get_features(struct hci_dev *hdev);
 int msft_add_monitor_pattern(struct hci_dev *hdev, struct adv_monitor *monitor);
 int msft_remove_monitor(struct hci_dev *hdev, struct adv_monitor *monitor);
 void msft_req_add_set_filter_enable(struct hci_request *req, bool enable);
+void msft_set_active_scan(struct hci_dev *hdev, bool enable);
 int msft_set_filter_enable(struct hci_dev *hdev, bool enable);
 int msft_suspend_sync(struct hci_dev *hdev);
 int msft_resume_sync(struct hci_dev *hdev);
@@ -55,6 +56,7 @@  static inline int msft_remove_monitor(struct hci_dev *hdev,
 
 static inline void msft_req_add_set_filter_enable(struct hci_request *req,
 						  bool enable) {}
+static inline void msft_set_active_scan(struct hci_dev *hdev, bool enable) {}
 static inline int msft_set_filter_enable(struct hci_dev *hdev, bool enable)
 {
 	return -EOPNOTSUPP;