Race condition for GPIO sharing between net core and app core

[darshan.patel]

Hello,

How race conditions are handled for GPIO forwarding  when done dynamically like this empty code sample , instead of using DTS entry  ?

Listed some scenarios, please clarify expected behavior.

1. Net core configures GPIO as output, then App core forwards that GPIO, expected behavior ?

2. App core sets as input, Net core sets as output, then App core forwards that GPIO, expected behavior ?

3. Net core configures GPIO as input, Tries to read value, then App core forwards that GPIO, expected behavior ?

4. Net core configure two GPIOs as UART, then App core forwards those GPIOs, expected behavior, can other side exchange UART TX and RX now ?

Is there a documentation regarding this race condition handling / best practices ?

Thanks,

Darshan

[Einar Thorsrud]

Hi,

There should not be any risk of such race conditions. The reason is that the network core is halted by default, and is started by the application core (after GPIO pin forwarding etc has been set up).

[darshan.patel]

what if we need dynamic sharing of GPIO ? I can have some IPC calls to coorndinate.

But just asking, what is expected behavior if

1. network core tries to read a GPIO that has not been forwarded by app core?

2. network core tries to Xmit and Receive data over UART when app core has not forwarded it.