releases/4.4.133/qmi_wwan-do-not-steal-interfaces-from-class-drivers.patch

   1 From foo@baz Wed May 16 16:57:32 CEST 2018
   2 From: "Bjørn Mork" <bjorn@mork.no>
   3 Date: Wed, 2 May 2018 22:22:54 +0200
   4 Subject: qmi_wwan: do not steal interfaces from class drivers
   5
   6 From: "Bjørn Mork" <bjorn@mork.no>
   7
   8 [ Upstream commit 5697db4a696c41601a1d15c1922150b4dbf5726c ]
   9
  10 The USB_DEVICE_INTERFACE_NUMBER matching macro assumes that
  11 the { vendorid, productid, interfacenumber } set uniquely
  12 identifies one specific function.  This has proven to fail
  13 for some configurable devices. One example is the Quectel
  14 EM06/EP06 where the same interface number can be either
  15 QMI or MBIM, without the device ID changing either.
  16
  17 Fix by requiring the vendor-specific class for interface number
  18 based matching.  Functions of other classes can and should use
  19 class based matching instead.
  20
  21 Fixes: 03304bcb5ec4 ("net: qmi_wwan: use fixed interface number matching")
  22 Signed-off-by: Bjørn Mork <bjorn@mork.no>
  23 Signed-off-by: David S. Miller <davem@davemloft.net>
  24 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  25 ---
  26  drivers/net/usb/qmi_wwan.c |   12 ++++++++++++
  27  1 file changed, 12 insertions(+)
  28
  29 --- a/drivers/net/usb/qmi_wwan.c
  30 +++ b/drivers/net/usb/qmi_wwan.c
  31 @@ -855,6 +855,18 @@ static int qmi_wwan_probe(struct usb_int
  32                 id->driver_info = (unsigned long)&qmi_wwan_info;
  33         }
  34
  35 +       /* There are devices where the same interface number can be
  36 +        * configured as different functions. We should only bind to
  37 +        * vendor specific functions when matching on interface number
  38 +        */
  39 +       if (id->match_flags & USB_DEVICE_ID_MATCH_INT_NUMBER &&
  40 +           desc->bInterfaceClass != USB_CLASS_VENDOR_SPEC) {
  41 +               dev_dbg(&intf->dev,
  42 +                       "Rejecting interface number match for class %02x\n",
  43 +                       desc->bInterfaceClass);
  44 +               return -ENODEV;
  45 +       }
  46 +
  47         /* Quectel EC20 quirk where we've QMI on interface 4 instead of 0 */
  48         if (quectel_ec20_detected(intf) && desc->bInterfaceNumber == 0) {
  49                 dev_dbg(&intf->dev, "Quectel EC20 quirk, skipping interface 0\n");