Hi,
in our product we have a usb modem connected to an AM3356 sitara custom board. to save power in situation were the modem have no traffic we would like to use the usb suspend resume functionality. the AM3356 is the USB host and the modem is the peripheral.
we did:
echo enabled > /sys/bus/usb/devices/1-1/power/wakeup
echo auto > /sys/bus/usb/devices/1-1/power/control
we left the autosuspend_delay_ms as 2000 since it is ok for our product.
we see that when there is no traffic for 2 seconds the USB go into suspend mode as expected , and also if we try to ping to a remote machine from the AM3356 cpu we see the usb wakes up and sends the pings.
the problem we have is that we have a system initiated traffic at this state (i.e. the remote machine ping to us) the modem does not wake the host.
to make sure this is not a modem issue we connected a normal mouse to the same USB while doing the exact same configuration and we saw the mouse also cannot wakeup the AM3356. The mouse can wakeup a laptop if connected to a laptop.
one more strange detail. if after we suspend the USB, we put the am335x into standby (echo standby > /sys/power/stat) and then we move the mouse, then we can wakeup the system from standby and the usb is also active.
can you please advise how to perform usb remote wakeup without putting sitara into standby?
