SPI loopback tests failing on MAX32 SoCs.

[ttmut]

Describe the bug

SPI loopback tests began to fail on MAX32 boards after the updates to SPI loopback tests: https://github.com/zephyrproject-rtos/zephyr/commits/main/tests/drivers/spi/spi_loopback/src?since=2025-03-21&until=2025-06-23

Failures are mostly related to word lengths other than 8-bits.

Regression

• This is a regression.

Steps to reproduce

> west build -p auto -b max32690evkit/max32690/m4 .\tests\drivers\spi\spi_loopback -T drivers.spi.loopback

Relevant log output

------ TESTSUITE SUMMARY START ------

SUITE PASS - 100.00% [spi_extra_api_features]: pass = 2, fail = 0, skip = 0, total = 2 duration = 0.007 seconds
 - PASS - [spi_extra_api_features.test_spi_hold_on_cs] duration = 0.005 seconds
 - PASS - [spi_extra_api_features.test_spi_lock_release] duration = 0.002 seconds

SUITE FAIL -  73.08% [spi_loopback]: pass = 19, fail = 7, skip = 0, total = 26 duration = 1.939 seconds
 - FAIL - [spi_loopback.test_nop_nil_bufs] duration = 0.216 seconds
 - PASS - [spi_loopback.test_spi_async_call] duration = 0.487 seconds
 - PASS - [spi_loopback.test_spi_complete_large_transfers] duration = 0.483 seconds
 - PASS - [spi_loopback.test_spi_complete_loop_mode_0] duration = 0.002 seconds
 - PASS - [spi_loopback.test_spi_complete_loop_mode_1] duration = 0.002 seconds
 - PASS - [spi_loopback.test_spi_complete_loop_mode_2] duration = 0.002 seconds
 - PASS - [spi_loopback.test_spi_complete_loop_mode_3] duration = 0.002 seconds
 - PASS - [spi_loopback.test_spi_complete_multiple] duration = 0.004 seconds
 - FLAKY - [spi_loopback.test_spi_complete_multiple_timed] - (Failed 1 of 2 attempts) - duration = 0.026 seconds
 - PASS - [spi_loopback.test_spi_concurrent_transfer_different_spec] duration = 0.007 seconds
 - PASS - [spi_loopback.test_spi_concurrent_transfer_same_spec] duration = 0.007 seconds
 - PASS - [spi_loopback.test_spi_null_rx_buf_set] duration = 0.002 seconds
 - PASS - [spi_loopback.test_spi_null_tx_buf] duration = 0.002 seconds
 - PASS - [spi_loopback.test_spi_null_tx_buf_set] duration = 0.002 seconds
 - FAIL - [spi_loopback.test_spi_null_tx_rx_buf_set] duration = 0.216 seconds
 - PASS - [spi_loopback.test_spi_rx_bigger_than_tx] duration = 0.002 seconds
 - PASS - [spi_loopback.test_spi_rx_every_4] duration = 0.002 seconds
 - PASS - [spi_loopback.test_spi_rx_half_end] duration = 0.002 seconds
 - PASS - [spi_loopback.test_spi_rx_half_start] duration = 0.002 seconds
 - PASS - [spi_loopback.test_spi_same_buf_cmd] duration = 0.003 seconds
 - FAIL - [spi_loopback.test_spi_word_size_16] duration = 0.217 seconds
 - FAIL - [spi_loopback.test_spi_word_size_24] duration = 0.015 seconds
 - FAIL - [spi_loopback.test_spi_word_size_32] duration = 0.015 seconds
 - PASS - [spi_loopback.test_spi_word_size_7] duration = 0.002 seconds
 - FAIL - [spi_loopback.test_spi_word_size_9] duration = 0.217 seconds
 - PASS - [spi_loopback.test_spi_write_back] duration = 0.002 seconds

 ------ TESTSUITE SUMMARY END ------

Impact

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

Environment

• OS: Windows
• Toolchain: Zephyr SDK 0.17.2
• v4.2.0

Additional Context

No response

[github-actions]

This issue has been marked as stale because it has been open (more than) 60 days with no activity. Remove the stale label or add a comment saying that you would like to have the label removed otherwise this issue will automatically be closed in 14 days. Note, that you can always re-open a closed issue at any time.

[ttmut]

Since the backport PR has been merged already, can this issue be closed?