I am still having issues in starting/stopping the remote firmware in the RPU. The RPU is running lwIP with SDK 2017.4 version. There should be a contention between the SCU timer (IRQ 29) and the "stop" mechanism required from remoteproc.
When I use the OpenAMP echo example, it works. Yet, using lwIP (it internally instantiates the SCU timer for tcp_fasttrm and tcp_slowtrm routines) the stop command replies as follows:
CPU1: failed to come online
zynq_remoteproc remoteproc@0: Can't power on cpu1 -5
remoteproc remoteproc0: stopped remote processor remoteproc@0
And the RPU firmware continues...
That happens each time I activate the lwIP stack, otherwise it works as expected.
brief update. The SCU interrupt timer seems not interfering with the remoteproc "stop" command. This has been verified with the FreeRTOS openAMP example, which it uses the SCU timer as tick handler. In that case, the CPU1/RPU is started and then stopped correctly.
I am currently investigating whether the gem0 IRQ used by the lwIP on CPU1/RPU might interfere with the openAMP. Still no luck so far.