[BUG] SPI_ENDSTOPS doesn't work for Dual-Y setups

[rondlh]

Did you test the latest bugfix-2.1.x code?

Yes, and the problem still exists.

Bug Description

Sensorless homing with SPI_ENDSTOPS doesn't work for dual-Y setups, the X-asis homes correctly.
If I use the hardware TMC5160 lines with endstops then it works fine for both X and Y.

Bug Timeline

Around a year ago it stopped working, I just tried it again, now the failure more is different

Expected behavior

Correct Y-homing for dual-Y setup (Y and Y2).

Actual behavior

Both Y-steppers do not move, the printer reports "Homing Failed" and shuts down.

SPI communication is working, I can setup the drivers mode (Stealth/Spreadcycle and current). No driver issues are reported at startup. All is working when using hardware endstops, just SPI_ENDSTOPS doesn't work.

Steps to Reproduce

1. Enable sensorless homing with suitable STALL_SENSITIVITY values (TMC5160 drivers)
2. Enable SPI_ENDSTOPS
3. Issue an G28Y

Version of Marlin Firmware

Latest bugfix (August 29 2024)

Printer model

Custom

Electronics

MKS Monster8 V1.0, TMC5160 drivers for X, Y and Y2

LCD/Controller

BTT TFT35 V3.0,

Other add-ons

BT Touch V3.1

Bed Leveling

ABL Bilinear mesh

Your Slicer

Cura

Host Software

None

Don't forget to include

• A ZIP file containing your Configuration.h and Configuration_adv.h.

Additional information & file uploads

Platform IO settings:
default_envs = mks_monster8_usb_flash_drive_msc

I removed the diagnostics jumpers for X, Y and Y2 when
testing SPI_ENDSTOPS.
M119 doesn't report the X and Y endstop status, so there I cannot see any status there.

Configuration_adv.zip