[PATCH] Bluetooth: btusb: fix NXP IW610 composite device handling

[Nicolas Thibert]

The NXP IW610 module exposes itself as a composite USB device
(0471:0215) with three interfaces: two real Bluetooth HCI interfaces
(class 0xe0) and one vendor-specific WiFi interface (class 0xff) used
by mwifiex-nxp.

The composite device's whole USB descriptor reports class 0xe0/01/01
(Bluetooth), so btusb_table's generic USB_DEVICE_INFO(0xe0, 0x01, 0x01)
entry matches every interface, not just the two real HCI ones -- btusb
ends up binding the WiFi interface too, and mwifiex-nxp never gets it.

Fix:
1. In btusb_table (the table the USB core actually matches against),
   explicitly ignore the WiFi interface via BTUSB_IGNORE, ahead of the
   generic entry.
2. In quirks_table, scope the existing BTUSB_MARVELL entry to the BT
   interface class instead of matching the whole device by VID/PID
   (harmless either way since quirks_table isn't consulted for initial
   binding, but keep it correct).

Not upstream anywhere: checked NXP's own i.MX kernel fork
(nxp-imx/linux-imx), no IW610 references in btusb.c on any branch --
their reference designs wire this chip differently (WiFi over SDIO
per their release notes), so they never hit this.

Signed-off-by: Nicolas Thibert <nithibert@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Assisted-by: LLM (Claude Sonnet 5, Anthropic)
---
 drivers/bluetooth/btusb.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -71,6 +71,15 @@ static struct usb_driver btusb_driver;
 #define BTUSB_BROKEN_EXT_SCAN		BIT(29)
 
 static const struct usb_device_id btusb_table[] = {
+	/*
+	 * NXP IW610 (0471:0215): the composite device reports Bluetooth
+	 * class at the whole-device level, so the generic entry below
+	 * would also match this WiFi vendor interface. Ignore it here
+	 * first so mwifiex-nxp can bind it instead.
+	 */
+	{ USB_DEVICE_AND_INTERFACE_INFO(0x0471, 0x0215, 0xff, 0xff, 0xff),
+	  .driver_info = BTUSB_IGNORE },
+
 	/* Generic Bluetooth USB device */
 	{ USB_DEVICE_INFO(0xe0, 0x01, 0x01) },
 
@@ -477,6 +486,14 @@ static const struct usb_device_id quirks
 	{ USB_DEVICE(0x1286, 0x2046), .driver_info = BTUSB_MARVELL },
 	{ USB_DEVICE(0x1286, 0x204e), .driver_info = BTUSB_MARVELL },
 
+	/*
+	 * NXP IW610 BT interfaces (Marvell-lineage silicon, same quirk as
+	 * the 0x1286 entries above). Scoped to the BT interface class,
+	 * not just VID/PID -- see the btusb_table entry above.
+	 */
+	{ USB_DEVICE_AND_INTERFACE_INFO(0x0471, 0x0215, 0xe0, 0x01, 0x01),
+	  .driver_info = BTUSB_MARVELL },
+
 	/* Intel Bluetooth devices */
 	{ USB_DEVICE(0x8087, 0x0025), .driver_info = BTUSB_INTEL_COMBINED },
 	{ USB_DEVICE(0x8087, 0x0026), .driver_info = BTUSB_INTEL_COMBINED },
--
2.34.1