Re: nm in different linux distributions - ppp versus qmi-wwan

[Bjørn Mork <bjorn mork no>]

Thomas Schäfer <tschaefer t-online de> writes:
> lsusb-20151106-suse.txt (good case)
> lsusb-20151106.txt (manjaro - bad case)
>
>
> both use kernel 4.1.x
>
> The diff is not big:

Yes, the device appears identical, switched to the same mode with a
single config.  This is as expected.

>     Interface Descriptor:
>       bLength                 9
>       bDescriptorType         4
>       bInterfaceNumber        3
>       bAlternateSetting       0
>       bNumEndpoints           1
>       bInterfaceClass       255 Vendor Specific Class
>       bInterfaceSubClass      1 
>       bInterfaceProtocol      9 
>       iInterface              0 
>       ** UNRECOGNIZED:  05 24 00 10 01
>       ** UNRECOGNIZED:  0d 24 0f 01 00 00 00 00 00 20 01 00 00
>       ** UNRECOGNIZED:  05 24 06 03 04
>       Endpoint Descriptor:
>         bLength                 7
>         bDescriptorType         5
>         bEndpointAddress     0x85  EP 5 IN
>         bmAttributes            3
>           Transfer Type            Interrupt
>           Synch Type               None
>           Usage Type               Data
>         wMaxPacketSize     0x0040  1x 64 bytes
>         bInterval               5
>     Interface Descriptor:
>       bLength                 9
>       bDescriptorType         4
>       bInterfaceNumber        4
>       bAlternateSetting       0
>       bNumEndpoints           2
>       bInterfaceClass       255 Vendor Specific Class
>       bInterfaceSubClass      1 
>       bInterfaceProtocol      8 
>       iInterface              0 



Interfaces 3 and 4 make a QMI function together. They are using Huaweis
well known QMI subclass/protocol values, and the control interface has a
valid union descriptor.  All looking good.  The mainline option driver
will not attempt to probe these interfaces by default.

> [  164.681791] option 4-2:1.3: GSM modem (1-port) converter detected
> [  164.682175] option 4-2:1.4: GSM modem (1-port) converter detected
> [  164.682557] usb 4-2: GSM modem (1-port) converter now attached to ttyUSB4


But the option driver erronously tries to bind (to both interfaces
actually).  Note that it even attempts to bind to interface #3. Which
fails of course, since there are no bulk endpoints.

This is obviously a misconfiguration of the option driver.  It could in
theory be patched, but I suspect some userspace script has been
"helpful", adding the device ID dynamically.  Could you post the output
of "cat /sys/bus/usb-serial/drivers/option1/new_id" as well?



Bjørn