Fix M876 called from EP (STM32F103, et.al.) #21210
Merged
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Description
This change fixes crashes on STM32F103 (and probably other platforms) with the mergency M876 parser.
The host_response_handler used for M876 is called on an interrupt routine for the emergency response handler. The original routine sent output to the serial port and this causes crashed on STM32F103.
The fix removes all serial output from the routine. This should not affect the essential functionality.
Requirements
Crash can be reproduced on boards using STM32F103, like teh BigTreeTech SKR mini E3 v1.2. A simple "M876 S0" already caused the crash.
Benefits
This change fixes crashes on STM32F103 (and probably other platforms) with the mergency M876 parser.
Configurations
EMERGENCY_PARSER and HOST_ACTION_COMMANDS need to be enabled
Related Issues
It might fix issues with confirmation via the screen, but I cannot test this myself:
bigtreetech/BIGTREETECH-TouchScreenFirmware#1528
bigtreetech/BIGTREETECH-TouchScreenFirmware#1571
bigtreetech/BIGTREETECH-TouchScreenFirmware#1590