[PATCH v2] USB: cdc-acm: add Whistler radio scanners TRX series support

[Johan Hovold <johan@kernel.org>]

Add support for Whistler radio scanners TRX series, which have a union
descriptor that designates a mass-storage interface as master. Handle
that by generalising the NO_DATA_INTERFACE quirk to allow us to fall
back to using the combined-interface detection.

Note that the NO_DATA_INTERFACE quirk was added by commit fd5054c169d2
("USB: cdc_acm: Fix oops when Droids MuIn LCD is connected") to handle a
combined-interface-type device with a broken call-management descriptor
by hardcoding the "data" interface number.

Link: https://lore.kernel.org/r/5f4ca4f8.1c69fb81.a4487.0f5f@mx.google.com
Reported-by: Daniel Caujolle-Bert <f1rmb.daniel@gmail.com>
Tested-by: Daniel Caujolle-Bert <f1rmb.daniel@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
---

v2
 - use the right class define in the device-id table (not subclass with
   same value)


 drivers/usb/class/cdc-acm.c | 36 ++++++++++++++++++++++++------------
 1 file changed, 24 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 7f6f3ab5b8a6..316203bab0b8 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1220,27 +1220,26 @@ static int acm_probe(struct usb_interface *intf,
 	if (cmgmd)
 		call_intf_num = cmgmd->bDataInterface;
 
-	if (!union_header) {
-		if (call_intf_num > 0) {
+	combined_interfaces = (quirks & NO_DATA_INTERFACE) != 0;
+
+	if (!union_header || combined_interfaces) {
+		if (call_intf_num > 0 && !combined_interfaces) {
 			dev_dbg(&intf->dev, "No union descriptor, using call management descriptor\n");
-			/* quirks for Droids MuIn LCD */
-			if (quirks & NO_DATA_INTERFACE) {
-				data_interface = usb_ifnum_to_if(usb_dev, 0);
-			} else {
-				data_intf_num = call_intf_num;
-				data_interface = usb_ifnum_to_if(usb_dev, data_intf_num);
-			}
+			data_intf_num = call_intf_num;
+			data_interface = usb_ifnum_to_if(usb_dev, data_intf_num);
 			control_interface = intf;
 		} else {
 			if (intf->cur_altsetting->desc.bNumEndpoints != 3) {
 				dev_dbg(&intf->dev,"No union descriptor, giving up\n");
 				return -ENODEV;
-			} else {
+			}
+
+			if (!combined_interfaces) {
 				dev_warn(&intf->dev,"No union descriptor, testing for castrated device\n");
 				combined_interfaces = 1;
-				control_interface = data_interface = intf;
-				goto look_for_collapsed_interface;
 			}
+			control_interface = data_interface = intf;
+			goto look_for_collapsed_interface;
 		}
 	} else {
 		data_intf_num = union_header->bSlaveInterface0;
@@ -1807,6 +1806,19 @@ static const struct usb_device_id acm_ids[] = {
 	.driver_info = CLEAR_HALT_CONDITIONS,
 	},
 
+	{ USB_DEVICE_INTERFACE_CLASS(0x2a59, 0x0010, USB_CLASS_COMM),	/* Whistler TRX-1 */
+	  .driver_info = NO_DATA_INTERFACE,
+	},
+	{ USB_DEVICE_INTERFACE_CLASS(0x2a59, 0x0011, USB_CLASS_COMM),	/* Whistler TRX-2 */
+	  .driver_info = NO_DATA_INTERFACE,
+	},
+	{ USB_DEVICE_INTERFACE_CLASS(0x2a59, 0x0012, USB_CLASS_COMM),	/* Whistler TRX-1e */
+	  .driver_info = NO_DATA_INTERFACE,
+	},
+	{ USB_DEVICE_INTERFACE_CLASS(0x2a59, 0x0013, USB_CLASS_COMM),	/* Whistler TRX-2e */
+	  .driver_info = NO_DATA_INTERFACE,
+	},
+
 	/* Nokia S60 phones expose two ACM channels. The first is
 	 * a modem and is picked up by the standard AT-command
 	 * information below. The second is 'vendor-specific' but
-- 
2.26.2