From dd522a7429b07e4441871ae75ebbfcf53635bdd4 Mon Sep 17 00:00:00 2001 From: Abhishek Pandit-Subedi Date: Wed, 11 Mar 2020 08:54:02 -0700 Subject: [PATCH] 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 Signed-off-by: Marcel Holtmann --- include/net/bluetooth/hci_core.h | 1 + net/bluetooth/hci_request.c | 166 +++++++++++++++++++++---------- 2 files changed, 113 insertions(+), 54 deletions(-) diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h index 1a4d732bdce6..2d58485d0335 100644 --- a/include/net/bluetooth/hci_core.h +++ b/include/net/bluetooth/hci_core.h @@ -607,6 +607,7 @@ struct hci_conn_params { struct hci_conn *conn; bool explicit_connect; + bool wakeable; }; extern struct list_head hci_dev_list; diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c index 051e1b16c988..11624645cfcf 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_dev_dbg(hdev, "Scanning is paused for suspend"); + return; + } + if (use_ext_scan(hdev)) { struct hci_cp_le_set_ext_scan_enable cp; @@ -670,15 +678,55 @@ 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_dev_dbg(req->hdev, "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_dev_dbg(hdev, "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 +734,14 @@ 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 +750,28 @@ 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 +785,17 @@ 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 +890,12 @@ 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_dev_dbg(hdev, "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 +926,17 @@ 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_dev_dbg(hdev, "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 +996,18 @@ 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_dev_dbg(hdev, "Request complete opcode=0x%x, status=0x%x", opcode, @@ -991,6 +1042,9 @@ 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); @@ -1018,6 +1072,8 @@ 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); @@ -1026,6 +1082,8 @@ 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); }