NXP RT1XXX platforms fail spi loopback word size 24 and 9 bits with DMA based LPSPI driver

[decsny]

Describe the bug

On RT1XXX platforms, the spi loopback test reports the spi_word_size_24 and spi_word_size_9 test cases fail using the DMA version of the driver (CONFIG_SPI_MCUX_LPSPI_DMA=y), which is the default one used for the test for this board.

Regression

• This is a regression.

Steps to reproduce

west build -p always -b mimxrt1050_evk tests/drivers/spi/spi_loopback
west flash

Relevant log output

- PASS - [spi_loopback.test_spi_word_size_16] duration = 0.001 seconds
 - FAIL - [spi_loopback.test_spi_word_size_24] duration = 0.022 seconds
 - PASS - [spi_loopback.test_spi_word_size_32] duration = 0.004 seconds
 - PASS - [spi_loopback.test_spi_word_size_7] duration = 0.001 seconds
 - FAIL - [spi_loopback.test_spi_word_size_9] duration = 0.020 seconds

Impact

Functional Limitation – Some features not working as expected, but system usable.

Environment

Zephyr SDK

Additional Context

These word size test cases are new.