It's happened that glitches on the STM32_RST and STM32_BOOT lines have put the STM32 companion microcontroller into DFU mode making it not boot its FW, rendering it useless for the user.
Considering that the STM32 companion microcontroller is always reset on a reboot or power cycle, resetting it once again in U-Boot SPL isn't going to hurt it any more.
For ATtiny companion microcontroller, the situation is a bit different because a reboot or power cycle doesn't reset it. Additionally, since it can only be reset with a UPDI reset on the STM32_RST line, and that is virtually impossible to mistakenly trigger, the ATtiny is unlikely to be in unwanted reset or enter reset because U-Boot toggles STM32_RST line.
This series adds this (sometimes) required reset of the MCU in U-Boot SPL on Ringneck PX30 to recover from this unwanted DFU state.
Signed-off-by: Quentin Schulz quentin.schulz@theobroma-systems.com --- Quentin Schulz (2): rockchip: ringneck-px30: always reset STM32 companion controller on boot rockchip: ringneck-px30: enable SPL_BOARD_INIT
.../ringneck_px30/ringneck-px30.c | 52 ++++++++++++++++++++++ configs/ringneck-px30_defconfig | 1 + 2 files changed, 53 insertions(+) --- base-commit: 351da15f71e3d70dbc63e90781b403415452d864 change-id: 20231024-ringneck-stm32-reset-b5b7e7355ae4
Best regards,