qmi_wwan: Support dynamic config on Quectel EP06

Quectel EP06 (and EM06/EG06) supports dynamic configuration of USB
interfaces, without the device changing VID/PID or configuration number.
When the configuration is updated and interfaces are added/removed, the
interface numbers change. This means that the current code for matching
EP06 does not work.

This patch removes the current EP06 interface number match, and replaces
it with a match on class, subclass and protocol. Unfortunately, matching
on those three alone is not enough, as the diag interface exports the
same values as QMI. The other serial interfaces + adb export different
values and do not match.

The diag interface only has two endpoints, while the QMI interface has
three. I have therefore added a check for number of interfaces, and we
ignore the interface if the number of endpoints equals two.

Signed-off-by: Kristian Evensen <kristian.evensen@gmail.com>
Acked-by: Bjørn Mork <bjorn@mork.no>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index cb0cc30c3d6a190e8d3132b6bab4c5d67e29979c..e3270deecec29db00de03d2e5ff020473807519d 100644 (file)
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -967,6 +967,13 @@ static const struct usb_device_id products[] = {
                USB_DEVICE_AND_INTERFACE_INFO(0x03f0, 0x581d, USB_CLASS_VENDOR_SPEC, 1, 7),
                .driver_info = (unsigned long)&qmi_wwan_info,
        },
+       {       /* Quectel EP06/EG06/EM06 */
+               USB_DEVICE_AND_INTERFACE_INFO(0x2c7c, 0x0306,
+                                             USB_CLASS_VENDOR_SPEC,
+                                             USB_SUBCLASS_VENDOR_SPEC,
+                                             0xff),
+               .driver_info        = (unsigned long)&qmi_wwan_info_quirk_dtr,
+       },
 
        /* 3. Combined interface devices matching on interface number */
        {QMI_FIXED_INTF(0x0408, 0xea42, 4)},    /* Yota / Megafon M100-1 */
@@ -1255,7 +1262,6 @@ static const struct usb_device_id products[] = {
        {QMI_QUIRK_SET_DTR(0x2c7c, 0x0121, 4)}, /* Quectel EC21 Mini PCIe */
        {QMI_QUIRK_SET_DTR(0x2c7c, 0x0191, 4)}, /* Quectel EG91 */
        {QMI_FIXED_INTF(0x2c7c, 0x0296, 4)},    /* Quectel BG96 */
-       {QMI_QUIRK_SET_DTR(0x2c7c, 0x0306, 4)}, /* Quectel EP06 Mini PCIe */
 
        /* 4. Gobi 1000 devices */
        {QMI_GOBI1K_DEVICE(0x05c6, 0x9212)},    /* Acer Gobi Modem Device */
@@ -1331,6 +1337,19 @@ static bool quectel_ec20_detected(struct usb_interface *intf)
        return false;
 }
 
+static bool quectel_ep06_diag_detected(struct usb_interface *intf)
+{
+       struct usb_device *dev = interface_to_usbdev(intf);
+       struct usb_interface_descriptor intf_desc = intf->cur_altsetting->desc;
+
+       if (le16_to_cpu(dev->descriptor.idVendor) == 0x2c7c &&
+           le16_to_cpu(dev->descriptor.idProduct) == 0x0306 &&
+           intf_desc.bNumEndpoints == 2)
+               return true;
+
+       return false;
+}
+
 static int qmi_wwan_probe(struct usb_interface *intf,
                          const struct usb_device_id *prod)
 {
@@ -1365,6 +1384,15 @@ static int qmi_wwan_probe(struct usb_interface *intf,
                return -ENODEV;
        }
 
+       /* Quectel EP06/EM06/EG06 supports dynamic interface configuration, so
+        * we need to match on class/subclass/protocol. These values are
+        * identical for the diagnostic- and QMI-interface, but bNumEndpoints is
+        * different. Ignore the current interface if the number of endpoints
+        * the number for the diag interface (two).
+        */
+       if (quectel_ep06_diag_detected(intf))
+               return -ENODEV;
+
        return usbnet_probe(intf, id);
 }