Re: [PATCH net-next v6 0/3] The huawei_cdc_ncm driver / E3276 problem

["Bjørn Mork" <bjorn@mork.no>]

Pasi Kärkkäinen <pasik@iki.fi> writes:

> # ifconfig wwp0s26u1u5i1
> wwp0s26u1u5i1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
>         inet 10.8.219.204  netmask 255.255.255.248  broadcast 10.8.219.207
>         inet6 fe80::e5b:8fff:fe27:9a64  prefixlen 64  scopeid 0x20<link>
>         ether 0c:5b:8f:27:9a:64  txqueuelen 1000  (Ethernet)
>         RX packets 0  bytes 0 (0.0 B)
>         RX errors 1493  dropped 0  overruns 0  frame 0
>
> Note the RX errors.. ? 


Yes, that is not expected and is quite possibly hiding the explanation.

Could you do a usbmon dump to try to capture the contents of the USB
buffers we drop here?  See
https://www.kernel.org/doc/Documentation/usb/usbmon.txt

Note that the text interface may truncate the buffers too early for the
result to be useful.  wireshark/thsark will for example allow you to
capture the whole buffer (when snooping on the "usbmonX" interface - not
the netdev!)

We also have a few debug messages in the driver for different types of
errors we drop.  Turning on those might explain something (assuming you
have DYNAMIC_DEBUG enabled):

  ethtool -s wwp0s26u1u5i1 msglvl rx_err on

Note that these will be logged at "debug" level, so you need to turn on
logging/showing such messages as well.



Bjørn