Bluetooth: Implement proper low-power support for Three-wire UART
This patch adds on-demand wakeup request sending (and re-sendind) when
we are in low-power state. When the controller enters this state it will
send a sleep message after which the host is not allowed to send any
other packets until a wakeup request has been sent and the woken message
received as a response to it. The wakeup requests are re-sent
periodically until a woken message is received.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
diff --git a/drivers/bluetooth/hci_h5.c b/drivers/bluetooth/hci_h5.c
index 6fb8d4e..8819ce8 100644
--- a/drivers/bluetooth/hci_h5.c
+++ b/drivers/bluetooth/hci_h5.c
@@ -81,7 +81,11 @@
H5_ACTIVE,
} state;
- bool sleeping;
+ enum {
+ H5_AWAKE,
+ H5_SLEEPING,
+ H5_WAKING_UP,
+ } sleep;
};
static void h5_reset_rx(struct h5 *h5);
@@ -111,6 +115,8 @@
struct sk_buff *skb;
unsigned long flags;
+ BT_DBG("%s", hu->hdev->name);
+
if (h5->state == H5_UNINITIALIZED)
h5_link_control(hu, sync_req, sizeof(sync_req));
@@ -122,6 +128,11 @@
goto wakeup;
}
+ if (h5->sleep != H5_AWAKE) {
+ h5->sleep = H5_SLEEPING;
+ goto wakeup;
+ }
+
BT_DBG("hu %p retransmitting %u pkts", hu, h5->unack.qlen);
spin_lock_irqsave_nested(&h5->unack.lock, flags, SINGLE_DEPTH_NESTING);
@@ -262,12 +273,15 @@
return;
} else if (memcmp(data, sleep_req, 2) == 0) {
BT_DBG("Peer went to sleep");
- h5->sleeping = true;
- h5_link_control(hu, wakeup_req, 2);
+ h5->sleep = H5_SLEEPING;
+ return;
} else if (memcmp(data, woken_req, 2) == 0) {
BT_DBG("Peer woke up");
- h5->sleeping = false;
- return;
+ h5->sleep = H5_AWAKE;
+ } else if (memcmp(data, wakeup_req, 2) == 0) {
+ BT_DBG("Peer requested wakeup");
+ h5_link_control(hu, woken_req, 2);
+ h5->sleep = H5_AWAKE;
} else {
BT_DBG("Link Control: 0x%02hhx 0x%02hhx", data[0], data[1]);
return;
@@ -625,6 +639,19 @@
unsigned long flags;
struct sk_buff *skb, *nskb;
+ if (h5->sleep != H5_AWAKE) {
+ const unsigned char wakeup_req[] = { 0x05, 0xfa };
+
+ if (h5->sleep == H5_WAKING_UP)
+ return NULL;
+
+ h5->sleep = H5_WAKING_UP;
+ BT_DBG("Sending wakeup request");
+
+ mod_timer(&h5->timer, jiffies + HZ / 100);
+ return h5_prepare_pkt(hu, HCI_3WIRE_LINK_PKT, wakeup_req, 2);
+ }
+
if ((skb = skb_dequeue(&h5->unrel)) != NULL) {
nskb = h5_prepare_pkt(hu, bt_cb(skb)->pkt_type,
skb->data, skb->len);