ESP32-C6: spi_loopback_dma example broken (but apparently not just the example)

[bjoernQ]

Bug description

Running the example prints this on ESP32-C6

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9] .. [73, 74, 75, 76, 77, 78, 79, 7a, 7b, 0]
[0, 1, 0, 0, 0, 0, 0, 1, 1, 1] .. [1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
[0, 2, 0, 0, 0, 0, 0, 1, 1, 1] .. [1, 1, 1, 1, 1, 1, 1, 1, 1, 1]

So, it's failing after the first iteration

The tests don't fail because they only test one transfer

Seems the offending commit is b5f0246

To Reproduce

Run the example

Expected behavior

Example works as before

Environment

Chip type: esp32c6 (revision v0.0)
Crystal frequency: 40 MHz
Flash size: 4MB
Features: WiFi 6, BT 5
MAC address: 60:55:f9:f6:01:78

esp-hal commit 562c891

[Dominaezzz]

It's probably the DMA timing issue now that TX is done after RX. See #1856 (comment)