topic Re: [MQX on K64] post a semaphore during an interrupt creates a hardfault in Kinetis Software Development Kit

[MQX on K64] post a semaphore during an interrupt creates a hardfault

samuelboivineau — Thu, 19 Nov 2015 16:19:28 GMT

Hello,

I have tried to use most of the project sai_demo to test the SAI peripheral, but I have been stuck for a few days by a semaphore posted during an interrupt that creates a hardfault. The target is a K64F120M.

In fsl_soundcard.c, the function OSA_SemaPost(&buffer->sem) is used by SND_TxCallback, called by SND_TxDmaCallback, that is called by a DMA interrupt if my understanding is correct :

- EDMA_DRV_InstallCallback(&ctrl->dma_channel, SND_TxDmaCallback, (void *)card);

In the MQX documentation, I don't see anything about interrupt context.

And if I follow the post of the semaphore, then the sw goes to _lwsem_post, and sees that the semaphore is at 0, and a task is waiting for it, so the task is set ready and _CHECK_RUN_SCHEDULER is called. Then I jump into my HardFault_Handler, and I got those registers :

r0 = 0x1

r1 = 0x2000049c

r2 = 0x1

r3 = 0x1

r12 = 0x1fff0be0

lr = 0x30ab3 => in the code of _lwsem_wait_ticks, after _sched_execute_scheduler_internal and the result.

pc = 0x4b6 => instruction "bx lr" in _sched_execute_scheduler_internal (defined by macro as _CHECK_RUN_SCHEDULER)

psr = 0x1000000

So is it ok to post a semaphore inside an interrupt ?

Maybe I have a missed some configuration ?

Currently I am doing some polling but it's not the aim for a rtos ...

What is also curious is the link register with a value with 3 at the end, there is no alignement required ? It would be some register over-written by someone ? but who ? And which stack or heap would be impacted ?

Thanks for your help

Re: [MQX on K64] post a semaphore during an interrupt creates a hardfault

keetle — Fri, 20 Nov 2015 00:58:27 GMT

I think you have met the same doubt I have before

I hope this link page will help you.

https://community.freescale.com/thread/379827

Re: [MQX on K64] post a semaphore during an interrupt creates a hardfault

samuelboivineau — Tue, 24 Nov 2015 12:16:50 GMT

Hello,

Thanks for your answer, I've looked at the link, but I am using the irq functions of the example, so it doesn't seem to be an issue. And I don't see how can I change it. They are defined this way :

// DMA (0 to 15)

void DMA0_IRQHandler(void)

{

EDMA_DRV_IRQHandler(0);

} [...]

// SAI

void I2S0_Tx_IRQHandler(void)

{

SAI_DRV_TxIRQHandler(0U);

}

void I2S0_Rx_IRQHandler(void)

{

SAI_DRV_RxIRQHandler(0U);

}

If anyone has an idea, let me know !

Regards

Re: [MQX on K64] post a semaphore during an interrupt creates a hardfault

keetle — Wed, 25 Nov 2015 02:13:42 GMT

It means that your interrup function name should not be same as the CMSIS startup code file interrupt function name.

so your function name "DMA0_IRQHandler" etc are illegal.

you can modify the illegal function name like this:

void MQX_DMA0_IRQHandler(void)

{

EDMA_DRV_IRQHandler(0);

}

after that, register interrupt function

_int_install_isr(DMA0_IRQn, (INT_ISR_FPTR)MQX_DMA0_IRQHandler, NULL);

after all, it should be OK.:smileyhappy:

Re: [MQX on K64] post a semaphore during an interrupt creates a hardfault

samuelboivineau — Wed, 25 Nov 2015 15:34:39 GMT

Hello,

Your solution solved the issue. Thanks a lot !