Hello @Maksh.1
Do you use the /dev/ttyRPMSG0 for IPCC communication between A7 and M4?
If yes, my hypothesis is that you are facing to a limitation of the RPMsg protocol.
To verify this, could perform following test: send a first RPMsg from the Cortex-A7 to the Cortex-M4 before sending RPMsgs from M4?
Related Explanation:
An RPMsg communication is the transmission of a message to a remote processor terminal, referenced by an endpoint address.
Thus, in order to transmit a message, the cortex-M4 must know the destination address of the Cortex-A7 endpoint.
The RPMSG TTY communication channel is initiated by the cortex-M4, on endpoint creation, by sending a special RPMsg named "name service annoucement".
In this message, the A7 can find a "service name" and the address of the Cortex-M4 endpoint. This probe the rpmsg_tty driver and mount the /dev/ttyRPMSG0
At this point, the Cortex-A7 can send a message to the Cortex-M4. But the Cortex-M4 cannot ( still doesn't have the Cortex-A7 endpoint address).
Sending a first "****" message from the Cortex-A7 to the Cortex-M4 provides the Cortex-A7 endpoint address to the Cortex-M4.
Then the Cortex-M4 can send messages.
Hope this will help!
Regards,
Arnaud
