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

[Dan Williams <dcbw@redhat.com>]

On Fri, 2014-03-14 at 16:25 +0200, Pasi Kärkkäinen wrote:
> On Fri, Mar 14, 2014 at 02:33:36PM +0100, Bjørn Mork wrote:
> > Pasi Kärkkäinen <pasik@iki.fi> writes:
> > > On Fri, Mar 14, 2014 at 10:24:51AM +0100, Bjørn Mork wrote:
> > >> 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.
> > >> 
> > >
> > > Ok, good to know.
> > >
> > >> 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!)
> > >> 
> > >
> > > I'll try that.. 
> > >
> > >> 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.
> > >> 
> > >
> > > # uname -a
> > > Linux localhost.localdomain 3.13.6-200.fc20.x86_64 #1 SMP Fri Mar 7 17:02:28 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux
> > >
> > > # grep -i DYNAMIC_DEBUG /boot/config-3.13.6-200.fc20.x86_64
> > > CONFIG_DYNAMIC_DEBUG=y
> > >
> > > # echo 8 > /proc/sys/kernel/printk
> > > # cat /proc/sys/kernel/printk
> > > 8       4       1       7
> > >
> > > # ethtool -s wwp0s26u1u5i1 msglvl rx_err on
> > >
> > > Is that enough?
> > 
> > I believe so, but I don't feel too steady on all the dynamic-ness here.
> > 
> > > I don't see any errors logged in "dmesg" output,
> > > but the RX errors counters do keep increasing in ifconfig output.. 
> > 
> > OK, let's see if we can figure it out based on the usbmon data.
> > 
> 
> http://pasik.reaktio.net/huawei-e3276-usbmon3.pcapng
> 
> (I did move the dongle to a different usb bus nr 3 to make it the only device on that bus before capturing..) 
> 
> So what I did:
> 
> - Start wireshark capture on USB bus nr 3.
> - Plug in the Huawei E3276 dongle.
> - Wait for usb_modeswitch to happen.
> - Use minicom to talk to /dev/cdc-wdm0 and send AT commands to connect to Internet:
> 	- ATQ0 V1 E1 S0=0
> 	- AT^NDISDUP=1,1,"internet"

Are you sure the device has actually registered with the network at the
point you do the NDISDUP?  At this point what do you get for "AT+CREG?"
and "AT+CFUN?" ?

Dan

> - After the dongle has connected query for DHCP status:
> 	- AT^DHCP?
> 
> - Launch dhcp client (dhclient) on wwp0s20u1i1 interface.
> - Wait for a while and see RX error counters increasing on ifconfig output.
> - Cancel (ctrl+c) the dhclient.
> - Stop wireshark capture. 
> 
> 
> Does that capture file show anything interesting to you? 
> 
> > 
> > 
> > Bjørn
> 
> 
> Thanks,
> 
> -- Pasi
> 
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