TMDS64EVM: Increasing optimization options makes ipc_rpmsg unstable

Kiyomasa Imaizumi

Part Number: TMDS64EVM

Tool/software:

Hello TI support team.

I have a question about ipc_rpmsg on AM64.
The SDK is mcu_plus_sdk_am64x_09_01_00_41.
The example ipc_rpmsg_echo_am64x-evm_a53ss0-0_nortos_gcc-aarch64 is used.

However, I am building the CA53 project with armclang to create the firmware.
armclang is version 6.6.

With the optimization option -O0, inter-core communication between CA53 and CR5 works correctly,
but when the option is changed to -O3, it sometimes stops working correctly.
It doesn't come out from RPMessage_recv. It seems that the semaphore is not posted and is waiting forever.

What modifications should I make to ipc_rpmsg.c etc. to make Ipc rpmsg work properly even when the optimization option is set to -O3?
I tried marking a variable (gIpcRpmsgCtrl) in ipc_rpmsg.c as volatile, but that didn't improve the situation.
I would like to use the optimization option -O3, so I would appreciate some advice on which parts of the source code I should change.

Please let me know if there are any parts of the ipc_rpmsg code that may not work due to optimizations.

Best regards,
Kiyomasa Imaizumi.

9 months ago

0 Kiyomasa Imaizumi 9 months ago

Intellectual 850 points

Additional information.
The files with the optimization options changed are as follows:
ipc_rpmsg.c
ipc_rpmsg_vring.c
ipc_notify_v0.c
ipc_notify_v0_cfg.c

Best regards,

Kiyomasa Imaizumi.

0 Paula Carrillo 9 months ago in reply to Kiyomasa Imaizumi

TI__Mastermind 40580 points

Hi Kiyomasa-san, questions comments below

- Only change to our ipc_rpmsg_echo out-of-box (OOB) demo was to enable -03? Or, is there any other change?

- As a test, can you change 'recvMsg' array as 'volatile'?

Fyi, below thread reported a similar issue (in their case they are using ipc_rpmsg_echo_linux), there user found issue was due to out-of-bounds issue in another module.

(+) AM62A7: Occasionally entering the HwiP_data_abort_handler interrupt service function - Processors forum - Processors - TI E2E support forums

So, wondering if in your case this issue is trigger with our OOB demo

thank you,

Paula

0 Kiyomasa Imaizumi 8 months ago in reply to Paula Carrillo

Intellectual 850 points

Hello Paula Carrillo

Thank you for your reply.

Which part of the code is the recvMsg' array made volatile?

It does not work with the ipc_rpmsg_echo sample project alone.
I have incorporated the ipc_rpmsg_echo code into our program using it as a reference.
I have added the following source code related to ipc_rpmsg_echo to my project and it is working.
I have not changed the following source code.
ipc_rpmsg.c
ipc_rpmsg_vring.c
ipc_notify_v0.c
ipc_notify_v0_cfg.c

I have marked inline and global variables as volatile as a test.
I will check the operation from now on, but it may not improve much.

Best regards,

Kiyomasa Imaizumi.

0 Paula Carrillo 8 months ago in reply to Kiyomasa Imaizumi

TI__Mastermind 40580 points

Hi Kiyomasa-san,

From examples\drivers\ipc\ipc_rpmsg_echo\ipc_rpmsg_echo.c you can find:

char recvMsg[MAX_MSG_SIZE];

You can give a try changing it to volatile

Let us know how your test goes.

thank you,

Paula