Gerard Cunningham wrote:
> Mostly the problem seems to be that Huawei (or maybe vodafone) puts a
> pile of autoloading Wincrap on the SD, which then confuses the kernel
> into thinking its a CD device. A Ubuntu attempt to make the kernel see
> the SD as a storage device had the unintended consequence of losing the
> 'modem' component of the dongle, and since it happened around kernel
> freeze time, people have been snookered.
>> At least, that's my non-tech take on it.
Good to hear you have it working.
Just to clarify (and I'm open to correction) the issue is that the linux
kernel probes new USB devices until it hits something it finds a match on.
Noone considered that a single USB device might be multiple things, so once it
finds a match, it stops looking. Since the USB modems are both 3G dongle (i.e.
a modem) and a mass storage device - and the kernel checks for mass storage
device first - it never bothers to continue checking to see if it also might
have the capabilities of a modem.
This is fixed by telling the kernel to keep looking for certain devices,
noted by their vendor and product IDs. I provided this ability to you in a
previous script, providing the capability to force the option (serial) module
to load for a particular USB device, so whether from my mails or otherwise,
glad to hear you have it working now :)
The Huawei E220 and E270 have had their product IDs added to the lookup
table, so a vanilla kernel will know to keep looking until it finds their
modem capabilities - however, Huawei are releasing modem models faster than
the kernel can release updates to the vendor/product ID list. No doubt in the
next releases of the kernel we'll see things like the E620, E1752 and the like
being supported without having to explicitly muck about with modprobe's
ordering of device discover.
Maintained by the ILUG website team. The aim of Linux.ie is to
support and help commercial and private users of Linux in Ireland. You can
display ILUG news in your own webpages, read backend
information to find out how. Networking services kindly provided by HEAnet, server kindly donated by
Dell. Linux is a trademark of Linus Torvalds,
used with permission. No penguins were harmed in the production or maintenance
of this highly praised website. Looking for the
Indian Linux Users' Group? Try here. If you've read all this and aren't a lawyer: you should be!