Hi, 2016-11-14 14:51 GMT+01:00 Daniele Palmas <dnlplm@xxxxxxxxx>: > Hi, > > I'm struggling with Telit LE922 modem that presents an MBIM device. > The modem works fine in Windows, while in Linux (tested with 4.9 rc1) > data connection is not functional: using ifconfig I can see > > wwp0s20u8i2 Link encap:Ethernet HWaddr e6:c0:3b:97:80:de > inet addr:176.246.94.9 Bcast:176.246.94.11 Mask:255.255.255.252 > UP BROADCAST RUNNING NOARP MULTICAST MTU:1500 Metric:1 > RX packets:0 errors:0 dropped:0 overruns:0 frame:0 > TX packets:1 errors:15 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:1000 > RX bytes:0 (0.0 B) TX bytes:40 (40.0 B) > > so the issue seems to be in tx. > > I'm using an USB hw sniffer for trying to understand the problem; this > is an example of a NCM packet with Windows 10 driver: > > 4E 43 4D 48 0C 00 0B 02 48 00 38 00 45 00 00 28 > 78 E8 40 00 80 06 63 68 05 5C 7A E5 D8 3A C6 03 > E9 08 01 BB FB 36 F0 EA C6 8C D8 CB 50 10 80 00 > 9B 16 00 00 00 00 00 00 49 50 53 00 10 00 00 00 > 0C 00 28 00 00 00 00 00 > > 16 bit NTB, with NDP at the end. So I enabled CDC_NCM_FLAG_NDP_TO_END, > but still the device is not properly working. > > This is the first properly transmitted acked packet in Linux: > > 4E 43 4D 48 0C 00 00 00 80 00 34 00 46 C0 00 28 > 00 00 40 00 01 02 F4 F9 B0 F6 5E 09 E0 00 00 16 > 94 04 00 00 22 00 F9 02 00 00 00 01 04 00 00 00 > E0 00 00 FB 49 50 53 00 10 00 00 00 0C 00 28 00 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > > that looks like quite similar than the Windows one (besides the final padding). > > Then all the following out packets are nacked, e.g: > > 4E 43 4D 48 0C 00 01 00 D8 00 8C 00 45 00 00 3E > 05 71 40 00 40 11 0C E8 B0 F6 5E 09 0A 85 0E D2 > B3 30 00 35 00 2A D3 57 58 6A 01 00 00 01 00 00 > 00 00 00 00 05 64 61 69 73 79 06 75 62 75 6E 74 > 75 03 63 6F 6D 00 00 01 00 01 00 00 45 00 00 3E > 2A EC 40 00 40 11 91 8A B0 F6 5E 09 0A 84 64 B5 > B3 30 00 35 00 2A 7D 75 58 6A 01 00 00 01 00 00 > 00 00 00 00 05 64 61 69 73 79 06 75 62 75 6E 74 > 75 03 63 6F 6D 00 00 01 00 01 00 00 49 50 53 00 > 14 00 00 00 0C 00 3E 00 4C 00 3E 00 00 00 00 00 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > 00 00 00 00 00 00 00 00 > > Those packets look good to me: the main difference with Windows is the > presence of more than one datagram, but, as far as I understand, this > should not be a problem since the modem reports: > > dwNtbInMaxSize=16384 dwNtbOutMaxSize=16384 wNdpOutPayloadRemainder=0 > wNdpOutDivisor=4 wNdpOutAlignment=4 wNtbOutMaxDatagrams=16 flags=0x20 > > while in Windows it seems that always only one datagram is sent. > > My thought is that the problem is in the modem firmware: in some way, > the first acked packet is breaking things inside the modem that is not > able to receive packets anymore, but maybe there is some other > problems in the tx packets created by the driver and I'm not able to > catch it. > I was wrong, the problem is not with the first packet. The problem is in cdc_ncm, function cdc_ncm_bind_common, line usleep_range(10000, 20000); It seems that LE922 needs an higher timeout; changing the line to usleep_range(70000, 80000); makes the modem to work fine. I will submit a patch for this. Regards, Daniele > Does someone have an hint about this? > > Is there a way to configure the cdc_mbim driver in order to have > exactly the same packet format sent in Windows? > > USB traces taken with TotalPhase Datacenter are available at > > https://drive.google.com/open?id=0B1kPnH2g8ISIZWJiV05qeWN5dVE > > Thanks, > Daniele -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
