Quoting Linus Gasser <list@xxxxxxxxxxxxxxxxxx>:
Le 09/01/14 14:27, Bjørn Mork a écrit :
Linus Gasser <list@xxxxxxxxxxxxxxxxxx> writes:
I'm trying to get an USB-modem running on a Smileplug, which is some
Arm7-device, using it with the kernel 3.12-6. As far as I can tell
it's an USB3-port. It works well with harddisks, but when I plug in
USB-modems, it always fails sooner or later.
Do you have this problem with different modems?
You could try a powered hub to eliminate any power related problems.
But if the port can power a harddisk spinning up, then I guess it should
handle the 3G modem power spikes too. Anyway, a hub is a cheap and
simple test.
I tried again - one modem seems to work fine,
That's good. Modems crashing is unfortunately common, but
several different modems with extreme stability problems is still
somewhat unlikely.
while the other quits with a lot of
Jan 09 18:02:58 Profeda-new kernel: option1 ttyUSB0:
option_instat_callback: error -71
But it doesn't disconnect!
-71 is -EPROTO, which tells us that the modem side of the USB transfer
failed. I believe this only happens if the modem dies without disconnecting
from the bus.
So I think this is another type of firmware crash, unless there is some
other really weird stuff going on here.
They also run in an ethernet-mode (using cdc_ether), I'll also try
that one (but it lacks some functions I need, like sending
USSD-codes).
So if you have some debugging advice, I'd like to do it...
Sorry, I don't have any other suggestion than using the modems/firmwares
you have found to be working.
Bjørn
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