IMX8MP ECSPI3 MISO Problem

[AlfTeleco]

Hello, 

We are having some problems using ECSPI3 at an imx8mp custom board. 

Mosi, SCLK and CS seems to be working okay, but MISO is no even working in loopback mode. 

Any idea? Is there any kernel problem or special configuration at dts? 

Thanks a lot!

[AlfTeleco]

Hi Igor and thanks for the quick answer. 

We are using imx kernel 5.4.70. The problem seems to be related to CS signal. CS seems to be going inactive between writes and reads, maybe making the slave become unavailable. The problem is shown in this picture: 

Any idea will be much appreciated, thank you 

[igorpadykov]

Hi Alvaro

what bsp used in the case. May be recommended to try latest Linux 5.10.35_2.0.0

https://source.codeaurora.org/external/imx/linux-imx/tree/?h=lf-5.10.y

with unit test

https://source.codeaurora.org/external/imx/imx-test/tree/test/mxc_spi_test?h=lf-5.10.y_2.0.0

Best regards
igor