Hi Da,

On Sat, 28 Jun 2025 at 09:15, Da Xue [off-list ref] wrote:

Regulators controlling the SD card power need some settling time for SD
cards to fully reset from UHS modes. The regulator framework seems to
ignore falling times set in the device tree causing a few boards with the
same hardware implementation to hang on reboot because the SD card still
had some voltage and did not reset properly to be initialized again.

Add a delay sufficiently long for the voltage to drop so that the SD card
can reset properly. Otherwise the reboot will hang at missing SD card
especially with Samsung cards.

Although the driver defines reset identifiers such as
RESET_SD_EMMC_A, RESET_SD_EMMC_B, and RESET_SD_EMMC_C,
It does not implement proper reset controller functionality,
specifically lacking support
for reset_control_assert() and reset_control_deassert() operations.

Thanks
-Anand