On Mar 13, 2006, at 2:14 AM, swclimber wrote:

Hi Guy,
I adjusted and recompiled the pxa.c serial driver in order to make my
Compact Flash GPRS modem work with Gumstix.
Eveythings work fine: pppd get connected and I'm able to surf the net.
The problem is that when I kill pppd (or the internet provvider cut me off
the network - in GPRS network  from time to time You are changed Your IP
address) I'm not able to talk to my CF modem anymore.
If I make :
cat /dev/ttyS0 &
echo at > /dev/ttyS0
the console hangs until I Ctrl-C the command and get back a "Interrupted
system call"(while before the modem returned an "OK").
At the begginning I thought it was the modem still connected to the GPRS
network (thus not processing the AT command), but this should not be the
case since in Windows I get a different behaviour (it works).
For my application it would be acceptable also restart the modem and even
the Gumstix (in auto mode not by operator action since the system is in a
remote geografic area), but even that seems not working:
cardctl suspend
cardctl resume
cardctl eject
cardctl insert
seems not to take away power from the CF sockect (the led is still blinking
even though "cardctl status" show no board after "eject" while after"
insert" it is shown back)
If I try "reboot -d 1", the processor reboot but it does not take away power
from the socket and the modem still does not start working (for some reasons
I not able to get back my serial console either...).
I'm frustrated because I'm not able to understand where the problem come
from and I ended all the testing I thought of in order to debug the problem.
Any help would be greatly appreciated.

If you remove power from the boards, then re-plug it, does it then work again?

When you say at the end "for some reasons I not able to get back my serial console either", what do you mean by that?