On Thu, 2012-05-17 at 01:11 +0200, Martin Mokrejs wrote: > Hi Bjorn, > > Bjørn Mork wrote: > > Martin Mokrejs <mmokrejs@xxxxxxxxxxxxxxxxxx> writes: > > > >> Hi, > >> while here is the discussion about 3G modems and whether they should use one or another > >> driver and that usbserial should be avoided, I just bought Huawei E372 but it is using on > >> 3.4-rc7 I see it uses: > >> > >> cdc_wdm > >> usbserial_generic > >> option > > > > It should not use usbserial_generic, but it should use the qmi_wwan > > driver in addition to cdc_wdm and option. Did you build that? It's new > > in 3.4 so you may need to enable it if you are reusing an old config. > > You'll find it under > > > > Device Drivers > > Network device support > > USB Network Adapters > > Multi-purpose USB Networking Framework > > QMI WWAN driver for Qualcomm MSM based 3G and LTE modems > > OK, thanks, I did not build the driver so far. So, now will have it on the next reboot. Great. ;) > As I understood from other todays emails I should use the wwan interface and forget about pppd. > Will adjust for that. This should also be made clear from the help texts that one should prefer > the wwan interface over AT modem like-one. > > > > in menuconfig. > > > >> I am attaching dmesg and lsusb info. Unfortunately, my Zyxel P-661HNU-F3 router is running > >> 2.6.20 kernel and while it was working with Huawei E1823 it does not detect the E372. :(( > >> What would you recommend me to do to get it working: 1) properly under current kernels, > >> 2) under the old kernel in the router? > > > > 2.6.20 is very old, but you might get it working in serial mode if you > > can get an existing driver to bind. I guess you'll need a recent > > usb_modeswitch config on it in any case, to get the device to switch to > > modem mode. > > There is not even udev on that router, no /usr/bin/eject so I am a bit clueless > what to do to switch the modem ... and how come that the E1823 worked at all. ;) > > > > >> Bus 002 Device 009: ID 12d1:1506 Huawei Technologies Co., Ltd. E398 LTE/UMTS/GSM Modem/Networkcard > > > > The problem is that Huawei in their wisdom didn't see any reason to use > > an unique product ID for each device. So you will see a number of > > different devices using the same ID. Hopefully they are somewhat > > compatible, but we don't really know much about that... > > > > To make these things even more complicated, there are also different > > modeswitch commands which will make the device change its USB descriptor > > layout. Some of these will also change the product ID. But it's still > > not unique. > > I understand, I know that when it acts as the CD-ROM device it has different PCI ID > compared to the one when switched into modem mode. > > > > > So you need to look at the label on the device to find out what it is. > > lsusb cannot tell you. > > Regarding the speeds, would I think more of the fact that pppd allows me at maximum 480000 baudrate > speed (if not only 115200) I should have ignored the "faster" speed of this new USB stick > as it is anyway internally in the computer handled at fairly low speed. And, not even > talking about the router which has like every other router 2.4 kernel (if not even 2.2 kernel) > and has maybe always usbserial doing the real job. Unfortunately one cannot re-flash every > device with OpenWRT or ddWRT, this Zyxel thing is one of the "unsupported" devices. > > I think I will return the Huawei E372 tomorrow. Can I ever use up the 42Mbps, or 21.6Mbps? > Hardly 5.76Mbps as far as I saw with the E1823 stick. It's not about baudrate, since as Greg has pointed out here, baudrate is completely meaningless with USB devices. It's more about PPP vs. network interface. PPP just has too much overhead and that's what slows things down when the device and tower have negotiated faster links like HSDPA 14.4 and up. Using PPP over these faster link rates is just a waste and usually only devices that support a network interface can provide full speed. PPP isn't used over-the-air with GSM/UMTS devices: it's only between the modem and the host. Devices that support network interfaces can completely skip the PPP framing and negotiation, saving quite a bit of overhead. Dan -- 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
