Switch from Managed and Ad-hoc mode

[ganglu]

Hi, folks,

I need switch my wavelan card from Managed and Ad-hoc mode in my
experiment to save power in an ipaq. It is like:

do{
switch to Ad-hoc mode;
transmite packets to server;
read packets from server;
switch to Managed mode;
sleep(1);
}while(1);

The problem is that very often the client got blocked in reading
packets: it has to wait a long time but it can received the packets
correctly. However If I ping the server in the same time, the client
correctly received the packets from server very quickly. That is really
confusing.

I used the ioctl (copied from the source code of iwconfig) to switch
the operation mode of Orinoco silver PC card. Its driver is wvlan_cs.
Is it possible the delay of the switch causing the problem?
But why if I ping the server at the same time, it works pretty good?

thanks,

gang lu