Merge tag 'for-net-2025-01-29' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth

Luiz Augusto von Dentz says:

====================
bluetooth pull request for net:

 - btusb: mediatek: Add locks for usb_driver_claim_interface()
 - L2CAP: accept zero as a special value for MTU auto-selection
 - btusb: Fix possible infinite recursion of btusb_reset
 - Add ABI doc for sysfs reset
 - btnxpuart: Fix glitches seen in dual A2DP streaming

* tag 'for-net-2025-01-29' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth:
  Bluetooth: L2CAP: accept zero as a special value for MTU auto-selection
  Bluetooth: btnxpuart: Fix glitches seen in dual A2DP streaming
  Bluetooth: Add ABI doc for sysfs reset
  Bluetooth: Fix possible infinite recursion of btusb_reset
  Bluetooth: btusb: mediatek: Add locks for usb_driver_claim_interface()
====================

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>

Author: Paolo Abeni

Documentation/ABI/stable/sysfs-class-bluetooth

@@ -0,0 +1,9 @@
+What: 		/sys/class/bluetooth/hci<index>/reset
+Date:		14-Jan-2025
+KernelVersion:	6.13
+Contact:	[email protected]
+Description: 	This write-only attribute allows users to trigger the vendor reset
+		method on the Bluetooth device when arbitrary data is written.
+		The reset may or may not be done through the device transport
+		(e.g., UART/USB), and can also be done through an out-of-band
+		approach such as GPIO.

MAINTAINERS

@@ -4078,6 +4078,7 @@ S:	Supported
 W:	http://www.bluez.org/
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth.git
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git
+F:	Documentation/ABI/stable/sysfs-class-bluetooth
 F:	include/net/bluetooth/
 F:	net/bluetooth/
 

drivers/bluetooth/btnxpuart.c

@@ -1381,13 +1381,12 @@ static void btnxpuart_tx_work(struct work_struct *work)
 
 	while ((skb = nxp_dequeue(nxpdev))) {
 		len = serdev_device_write_buf(serdev, skb->data, skb->len);
-		serdev_device_wait_until_sent(serdev, 0);
 		hdev->stat.byte_tx += len;
 
 		skb_pull(skb, len);
 		if (skb->len > 0) {
 			skb_queue_head(&nxpdev->txq, skb);
-			break;
+			continue;
 		}
 
 		switch (hci_skb_pkt_type(skb)) {

drivers/bluetooth/btusb.c

@@ -899,11 +899,6 @@ static void btusb_reset(struct hci_dev *hdev)
 	struct btusb_data *data;
 	int err;
 
-	if (hdev->reset) {
-		hdev->reset(hdev);
-		return;
-	}
-
 	data = hci_get_drvdata(hdev);
 	/* This is not an unbalanced PM reference since the device will reset */
 	err = usb_autopm_get_interface(data->intf);
@@ -2639,8 +2634,15 @@ static void btusb_mtk_claim_iso_intf(struct btusb_data *data)
 	struct btmtk_data *btmtk_data = hci_get_priv(data->hdev);
 	int err;
 
+	/*
+	 * The function usb_driver_claim_interface() is documented to need
+	 * locks held if it's not called from a probe routine. The code here
+	 * is called from the hci_power_on workqueue, so grab the lock.
+	 */
+	device_lock(&btmtk_data->isopkt_intf->dev);
 	err = usb_driver_claim_interface(&btusb_driver,
 					 btmtk_data->isopkt_intf, data);
+	device_unlock(&btmtk_data->isopkt_intf->dev);
 	if (err < 0) {
 		btmtk_data->isopkt_intf = NULL;
 		bt_dev_err(data->hdev, "Failed to claim iso interface");

net/bluetooth/l2cap_sock.c

@@ -710,12 +710,12 @@ static bool l2cap_valid_mtu(struct l2cap_chan *chan, u16 mtu)
 {
 	switch (chan->scid) {
 	case L2CAP_CID_ATT:
-		if (mtu < L2CAP_LE_MIN_MTU)
+		if (mtu && mtu < L2CAP_LE_MIN_MTU)
 			return false;
 		break;
 
 	default:
-		if (mtu < L2CAP_DEFAULT_MIN_MTU)
+		if (mtu && mtu < L2CAP_DEFAULT_MIN_MTU)
 			return false;
 	}