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Message-Id: <20200224160019.RFC.v3.4.Ib0d1956aff8b9b0eff8efff085675f2156fe91c5@changeid>
Date: Mon, 24 Feb 2020 16:00:35 -0800
From: Abhishek Pandit-Subedi <abhishekpandit@...omium.org>
To: marcel@...tmann.org, luiz.dentz@...il.com, alainm@...omium.org
Cc: linux-bluetooth@...r.kernel.org,
chromeos-bluetooth-upstreaming@...omium.org,
Abhishek Pandit-Subedi <abhishekpandit@...omium.org>,
"David S. Miller" <davem@...emloft.net>,
Johan Hedberg <johan.hedberg@...il.com>,
netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
Jakub Kicinski <kuba@...nel.org>
Subject: [RFC PATCH v3 4/5] Bluetooth: Handle LE devices during suspend
To handle LE devices, we must first disable passive scanning and
disconnect all connected devices. Once that is complete, we update the
whitelist and re-enable scanning
Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@...omium.org>
---
Changes in v3:
* Split LE changes into its own commit
Changes in v2: None
net/bluetooth/hci_request.c | 164 ++++++++++++++++++++++++------------
1 file changed, 110 insertions(+), 54 deletions(-)
diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index 4d67b1d08608..88fd95d70f89 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -34,6 +34,9 @@
#define HCI_REQ_PEND 1
#define HCI_REQ_CANCELED 2
+#define LE_SUSPEND_SCAN_WINDOW 0x0012
+#define LE_SUSPEND_SCAN_INTERVAL 0x0060
+
void hci_req_init(struct hci_request *req, struct hci_dev *hdev)
{
skb_queue_head_init(&req->cmd_q);
@@ -654,6 +657,11 @@ void hci_req_add_le_scan_disable(struct hci_request *req)
{
struct hci_dev *hdev = req->hdev;
+ if (hdev->scanning_paused) {
+ BT_DBG("Scanning is paused for suspend");
+ return;
+ }
+
if (use_ext_scan(hdev)) {
struct hci_cp_le_set_ext_scan_enable cp;
@@ -670,15 +678,53 @@ void hci_req_add_le_scan_disable(struct hci_request *req)
}
}
-static void add_to_white_list(struct hci_request *req,
- struct hci_conn_params *params)
+static void del_from_white_list(struct hci_request *req, bdaddr_t *bdaddr,
+ u8 bdaddr_type)
+{
+ struct hci_cp_le_del_from_white_list cp;
+
+ cp.bdaddr_type = bdaddr_type;
+ bacpy(&cp.bdaddr, bdaddr);
+
+ BT_DBG("Remove %pMR (0x%x) from whitelist", &cp.bdaddr, cp.bdaddr_type);
+ hci_req_add(req, HCI_OP_LE_DEL_FROM_WHITE_LIST, sizeof(cp), &cp);
+}
+
+/* Adds connection to white list if needed. On error, returns -1. */
+static int add_to_white_list(struct hci_request *req,
+ struct hci_conn_params *params, u8 *num_entries,
+ bool allow_rpa)
{
struct hci_cp_le_add_to_white_list cp;
+ struct hci_dev *hdev = req->hdev;
+
+ /* Already in white list */
+ if (hci_bdaddr_list_lookup(&hdev->le_white_list, ¶ms->addr,
+ params->addr_type))
+ return 0;
+
+ /* Select filter policy to accept all advertising */
+ if (*num_entries >= hdev->le_white_list_size)
+ return -1;
+ /* White list can not be used with RPAs */
+ if (!allow_rpa &&
+ hci_find_irk_by_addr(hdev, ¶ms->addr, params->addr_type)) {
+ return -1;
+ }
+
+ /* During suspend, only wakeable devices can be in whitelist */
+ if (hdev->suspended && !params->wakeable)
+ return 0;
+
+ *num_entries += 1;
cp.bdaddr_type = params->addr_type;
bacpy(&cp.bdaddr, ¶ms->addr);
+ BT_DBG("Add %pMR (0x%x) to whitelist", &cp.bdaddr, cp.bdaddr_type);
hci_req_add(req, HCI_OP_LE_ADD_TO_WHITE_LIST, sizeof(cp), &cp);
+
+ return 0;
}
static u8 update_white_list(struct hci_request *req)
@@ -686,7 +732,14 @@ static u8 update_white_list(struct hci_request *req)
struct hci_dev *hdev = req->hdev;
struct hci_conn_params *params;
struct bdaddr_list *b;
- uint8_t white_list_entries = 0;
+ u8 num_entries = 0;
+ bool pend_conn, pend_report;
+ /* We allow whitelisting even with RPAs in suspend. In the worst case,
+ * we won't be able to wake from devices that use the privacy1.2
+ * features. Additionally, once we support privacy1.2 and IRK
+ * offloading, we can update this to also check for those conditions.
+ */
+ bool allow_rpa = hdev->suspended;
/* Go through the current white list programmed into the
* controller one by one and check if that address is still
@@ -695,29 +748,28 @@ static u8 update_white_list(struct hci_request *req)
* command to remove it from the controller.
*/
list_for_each_entry(b, &hdev->le_white_list, list) {
- /* If the device is neither in pend_le_conns nor
- * pend_le_reports then remove it from the whitelist.
+ pend_conn = hci_pend_le_action_lookup(&hdev->pend_le_conns,
+ &b->bdaddr,
+ b->bdaddr_type);
+ pend_report = hci_pend_le_action_lookup(&hdev->pend_le_reports,
+ &b->bdaddr,
+ b->bdaddr_type);
+
+ /* If the device is not likely to connect or report,
+ * remove it from the whitelist.
*/
- if (!hci_pend_le_action_lookup(&hdev->pend_le_conns,
- &b->bdaddr, b->bdaddr_type) &&
- !hci_pend_le_action_lookup(&hdev->pend_le_reports,
- &b->bdaddr, b->bdaddr_type)) {
- struct hci_cp_le_del_from_white_list cp;
-
- cp.bdaddr_type = b->bdaddr_type;
- bacpy(&cp.bdaddr, &b->bdaddr);
-
- hci_req_add(req, HCI_OP_LE_DEL_FROM_WHITE_LIST,
- sizeof(cp), &cp);
+ if (!pend_conn && !pend_report) {
+ del_from_white_list(req, &b->bdaddr, b->bdaddr_type);
continue;
}
- if (hci_find_irk_by_addr(hdev, &b->bdaddr, b->bdaddr_type)) {
- /* White list can not be used with RPAs */
+ /* White list can not be used with RPAs */
+ if (!allow_rpa &&
+ hci_find_irk_by_addr(hdev, &b->bdaddr, b->bdaddr_type)) {
return 0x00;
}
- white_list_entries++;
+ num_entries++;
}
/* Since all no longer valid white list entries have been
@@ -731,47 +783,17 @@ static u8 update_white_list(struct hci_request *req)
* white list.
*/
list_for_each_entry(params, &hdev->pend_le_conns, action) {
- if (hci_bdaddr_list_lookup(&hdev->le_white_list,
- ¶ms->addr, params->addr_type))
- continue;
-
- if (white_list_entries >= hdev->le_white_list_size) {
- /* Select filter policy to accept all advertising */
+ if (add_to_white_list(req, params, &num_entries, allow_rpa))
return 0x00;
- }
-
- if (hci_find_irk_by_addr(hdev, ¶ms->addr,
- params->addr_type)) {
- /* White list can not be used with RPAs */
- return 0x00;
- }
-
- white_list_entries++;
- add_to_white_list(req, params);
}
/* After adding all new pending connections, walk through
* the list of pending reports and also add these to the
- * white list if there is still space.
+ * white list if there is still space. Abort if space runs out.
*/
list_for_each_entry(params, &hdev->pend_le_reports, action) {
- if (hci_bdaddr_list_lookup(&hdev->le_white_list,
- ¶ms->addr, params->addr_type))
- continue;
-
- if (white_list_entries >= hdev->le_white_list_size) {
- /* Select filter policy to accept all advertising */
+ if (add_to_white_list(req, params, &num_entries, allow_rpa))
return 0x00;
- }
-
- if (hci_find_irk_by_addr(hdev, ¶ms->addr,
- params->addr_type)) {
- /* White list can not be used with RPAs */
- return 0x00;
- }
-
- white_list_entries++;
- add_to_white_list(req, params);
}
/* Select filter policy to use white list */
@@ -866,6 +888,12 @@ void hci_req_add_le_passive_scan(struct hci_request *req)
struct hci_dev *hdev = req->hdev;
u8 own_addr_type;
u8 filter_policy;
+ u8 window, interval;
+
+ if (hdev->scanning_paused) {
+ BT_DBG("Scanning is paused for suspend");
+ return;
+ }
/* Set require_privacy to false since no SCAN_REQ are send
* during passive scanning. Not using an non-resolvable address
@@ -896,8 +924,17 @@ void hci_req_add_le_passive_scan(struct hci_request *req)
(hdev->le_features[0] & HCI_LE_EXT_SCAN_POLICY))
filter_policy |= 0x02;
- hci_req_start_scan(req, LE_SCAN_PASSIVE, hdev->le_scan_interval,
- hdev->le_scan_window, own_addr_type, filter_policy);
+ if (hdev->suspended) {
+ window = LE_SUSPEND_SCAN_WINDOW;
+ interval = LE_SUSPEND_SCAN_INTERVAL;
+ } else {
+ window = hdev->le_scan_window;
+ interval = hdev->le_scan_interval;
+ }
+
+ BT_DBG("LE passive scan with whitelist = %d", filter_policy);
+ hci_req_start_scan(req, LE_SCAN_PASSIVE, interval, window,
+ own_addr_type, filter_policy);
}
static u8 get_adv_instance_scan_rsp_len(struct hci_dev *hdev, u8 instance)
@@ -957,6 +994,18 @@ static void hci_req_set_event_filter(struct hci_request *req)
hci_req_add(req, HCI_OP_WRITE_SCAN_ENABLE, 1, &scan);
}
+static void hci_req_config_le_suspend_scan(struct hci_request *req)
+{
+ /* Can't change params without disabling first */
+ hci_req_add_le_scan_disable(req);
+
+ /* Configure params and enable scanning */
+ hci_req_add_le_passive_scan(req);
+
+ /* Block suspend notifier on response */
+ set_bit(SUSPEND_SCAN_ENABLE, req->hdev->suspend_tasks);
+}
+
static void suspend_req_complete(struct hci_dev *hdev, u8 status, u16 opcode)
{
BT_DBG("Request complete opcode=0x%x, status=0x%x", opcode, status);
@@ -991,6 +1040,9 @@ void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
page_scan = SCAN_DISABLED;
hci_req_add(&req, HCI_OP_WRITE_SCAN_ENABLE, 1, &page_scan);
+ /* Disable LE passive scan */
+ hci_req_add_le_scan_disable(&req);
+
/* Mark task needing completion */
set_bit(SUSPEND_SCAN_DISABLE, hdev->suspend_tasks);
@@ -1017,6 +1069,8 @@ void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
hdev->scanning_paused = false;
/* Enable event filter for paired devices */
hci_req_set_event_filter(&req);
+ /* Enable passive scan at lower duty cycle */
+ hci_req_config_le_suspend_scan(&req);
/* Pause scan changes again. */
hdev->scanning_paused = true;
hci_req_run(&req, suspend_req_complete);
@@ -1025,6 +1079,8 @@ void hci_req_prepare_suspend(struct hci_dev *hdev, enum suspended_state next)
hdev->scanning_paused = false;
hci_req_clear_event_filter(&req);
+ /* Reset passive/background scanning to normal */
+ hci_req_config_le_suspend_scan(&req);
hci_req_run(&req, suspend_req_complete);
}
--
2.25.0.265.gbab2e86ba0-goog
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