bluetooth: host: att: Implement disconnect on ATT timeout (f712bde1) · Commits · Wenxi XU / zephyr

doc/connectivity/bluetooth/bluetooth-le-host.rst

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		@@ -274,6 +274,19 @@ over LE connections. A more detailed description of this layer and the
		API reference can be found in the
		:ref:`GATT API reference section <bt_gatt>`.

		ATT timeout
		-----------

		If the peer device does not respond to an ATT request (such as read or write)
		within the ATT timeout, the host will automatically initiate a disconnect. This
		simplifies error handling by reducing rare failure conditions to a common
		disconnection, allowing developers to manage unexpected disconnects without
		special cases for ATT timeouts.

		.. image:: img/att_timeout.svg
		:align: center
		:alt: ATT timeout

		Mesh
		====

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		@@ -108,6 +108,8 @@ Bluetooth
		* Added API :c:func:`bt_gatt_get_uatt_mtu` to get current Unenhanced ATT MTU of a given
		connection (experimental).

		* The host now disconnects from the peer upon ATT timeout.

		* HCI Drivers

		Boards & SoC Support

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		@@ -3135,9 +3135,10 @@ static void att_timeout(struct k_work *work)
		struct k_work_delayable *dwork = k_work_delayable_from_work(work);
		struct bt_att_chan *chan = CONTAINER_OF(dwork, struct bt_att_chan,
		timeout_work);
		int err;

		bt_addr_le_to_str(bt_conn_get_dst(chan->att->conn), addr, sizeof(addr));
		LOG_ERR("ATT Timeout for device %s", addr);
		LOG_ERR("ATT Timeout for device %s. Disconnecting...", addr);

		/* BLUETOOTH SPECIFICATION Version 4.2 [Vol 3, Part F] page 480:
		*
		@@ -3148,6 +3149,16 @@ static void att_timeout(struct k_work *work)
		* target device on this ATT Bearer.
		*/
		bt_att_disconnected(&chan->chan.chan);

		/* The timeout state is local and can block new ATT operations, but does not affect the
		* remote side. Disconnecting the GATT connection upon ATT timeout simplifies error handling
		* for developers. This reduces rare failure conditions to a common one, allowing developers
		* to handle unexpected disconnections without needing special cases for ATT timeouts.
		*/
		err = bt_conn_disconnect(chan->chan.chan.conn, BT_HCI_ERR_REMOTE_USER_TERM_CONN);
		if (err) {
		LOG_ERR("Disconnecting failed (err %d)", err);
		}
		}

		static struct bt_att_chan att_get_fixed_chan(struct bt_conn conn)