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Commit 95c5c220 authored by Johan Hedberg's avatar Johan Hedberg Committed by Gustavo Padovan
Browse files

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: default avatarJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: default avatarGustavo Padovan <gustavo.padovan@collabora.co.uk>
parent f674a057

drivers/bluetooth/hci_h5.c

+32 −5
Original line number Diff line number Diff line
@@ -81,7 +81,11 @@ struct h5 { 
		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 @@ static void h5_timed_event(unsigned long arg) 
	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 @@ static void h5_timed_event(unsigned long arg) 
		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 @@ static void h5_handle_internal_rx(struct hci_uart *hu) 
		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 @@ static struct sk_buff *h5_dequeue(struct hci_uart *hu) 
	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);