On Sat, 2018-09-08 at 14:57 +0200, Kristian Evensen wrote: > The Quectel EP06 (and EM06/EG06) LTE modem supports updating the USB > configuration, without the VID/PID or configuration number changing. > When the configuration is updated and interfaces are added/removed, > the > interface numbers are updated. This causes our current code for > matching > EP06 not to work as intended, as the assumption about reserved > interfaces no longer holds. If for example the diagnostic (first) > interface is removed, option will (try to) bind to the QMI interface. > > This patch improves EP06 detection by replacing the current match > with > two matches, and those matches check class, subclass and protocol as > well as VID and PID. The diag interface exports class, subclass and > protocol as 0xff. For the other serial interfaces, class is 0xff and > subclass and protocol are both 0x0. > > The modem can export the following devices and always in this order: > diag, nmea, at, ppp. qmi and adb. This means that diag can only ever > be > interface 0, and interface numbers 1-5 should be marked as reserved. > The > three other serial devices can have interface numbers 0-3, but I have > not marked any interfaces as reserved. The reason is that the serial > devices are the only interfaces exported by the device where subclass > and protocol is 0x0. > > QMI exports the same class, subclass and protocol values as the diag > interface. However, the two interfaces have different number of > endpoints, QMI has three and diag two. I have added a check for > number > of interfaces if VID/PID matches the EP06, and we ignore the device > if > number of interfaces equals three (and subclass is set).
I double-checked the permutations & logic and it makes sense to me. Acked-by: Dan Williams <[email protected]> > Signed-off-by: Kristian Evensen <[email protected]> > --- > drivers/usb/serial/option.c | 17 +++++++++++++++-- > 1 file changed, 15 insertions(+), 2 deletions(-) > > diff --git a/drivers/usb/serial/option.c > b/drivers/usb/serial/option.c > index 0215b70c4efc..835dcd2875a7 100644 > --- a/drivers/usb/serial/option.c > +++ b/drivers/usb/serial/option.c > @@ -1081,8 +1081,9 @@ static const struct usb_device_id option_ids[] > = { > .driver_info = RSVD(4) }, > { USB_DEVICE(QUECTEL_VENDOR_ID, QUECTEL_PRODUCT_BG96), > .driver_info = RSVD(4) }, > - { USB_DEVICE(QUECTEL_VENDOR_ID, QUECTEL_PRODUCT_EP06), > - .driver_info = RSVD(4) | RSVD(5) }, > + { USB_DEVICE_AND_INTERFACE_INFO(QUECTEL_VENDOR_ID, > QUECTEL_PRODUCT_EP06, 0xff, 0xff, 0xff), > + .driver_info = RSVD(1) | RSVD(2) | RSVD(3) | RSVD(4) | > RSVD(5) }, > + { USB_DEVICE_AND_INTERFACE_INFO(QUECTEL_VENDOR_ID, > QUECTEL_PRODUCT_EP06, 0xff, 0, 0) }, > { USB_DEVICE(CMOTECH_VENDOR_ID, CMOTECH_PRODUCT_6001) }, > { USB_DEVICE(CMOTECH_VENDOR_ID, CMOTECH_PRODUCT_CMU_300) }, > { USB_DEVICE(CMOTECH_VENDOR_ID, CMOTECH_PRODUCT_6003), > @@ -1985,6 +1986,7 @@ static int option_probe(struct usb_serial > *serial, > { > struct usb_interface_descriptor *iface_desc = > &serial->interface->cur_altsetting- > >desc; > + struct usb_device_descriptor *dev_desc = &serial->dev- > >descriptor; > unsigned long device_flags = id->driver_info; > > /* Never bind to the CD-Rom emulation interface */ > @@ -1999,6 +2001,17 @@ static int option_probe(struct usb_serial > *serial, > if (device_flags & RSVD(iface_desc->bInterfaceNumber)) > return -ENODEV; > > + /* > + * Don't bind to the QMI device of the Quectel > EP06/EG06/EM06. Class, > + * subclass and protocol is 0xff for both the diagnostic > port and the > + * QMI interface, but the diagnostic port only has two > endpoints (QMI > + * has three). > + */ > + if (dev_desc->idVendor == cpu_to_le16(QUECTEL_VENDOR_ID) && > + dev_desc->idProduct == cpu_to_le16(QUECTEL_PRODUCT_EP06) > && > + iface_desc->bInterfaceSubClass && iface_desc- > >bNumEndpoints == 3) > + return -ENODEV; > + > /* Store the device flags so we can use them during attach. > */ > usb_set_serial_data(serial, (void *)device_flags); >
