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@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit is contained in:
Abhishek Pandit-Subedi 2020-03-11 08:54:02 -07:00 committed by Marcel Holtmann
parent 4f40afc6c7
commit dd522a7429
2 changed files with 113 additions and 54 deletions

View File

@ -607,6 +607,7 @@ struct hci_conn_params {
struct hci_conn *conn;
bool explicit_connect;
bool wakeable;
};
extern struct list_head hci_dev_list;

View File

@ -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, &params->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, &params->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, &params->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 */
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
@ -731,49 +785,19 @@ 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,
&params->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, &params->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,
&params->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, &params->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 */
return 0x01;
}
@ -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);
}