SAI can't work in M4 in stm32mp157,when A7 is running.

[csm]

hi,

I use SAI interface for reading data  by M4 core in stm32mp157

Only  in debug M4 mode(M4 is running and A7 isn't running),the read can success.

When A7 core is running, the read will be failed(A7 is running ,but SAI is used by M4).

 

when a7 is running.

Using HAL_SAI_Receive , time out will bu return .

Using HAL_SAI_Receive_DMA ,busy will be return .

in device tree ,sai is disable

[PatrickF]

Hi @csm 

have you adapted the Device Tree to tell Linux that SAI is handled by Cortex-M4 and SAI related clocks should be enabled ?
Please have a look to

https://wiki.st.com/stm32mpu/wiki/How_to_configure_system_resources#Configuring_clock_and_regulator_system_resources

 

Regards

[csm]

Apart from this reason  PatrickF mentioned, there is another reason。

Device tree use one of SAI  pins as other functions ，that I ignored 。