This sends a soft reset ping to the PBL, clearing the stuck state and re-initializing the Sahara protocol. For many OnePlus and Xiaomi users, this has turned a "dead motherboard" into a recoverable device.
In newer firmware versions (often starting with Android 10/11 updates), manufacturers made it harder to access EDL by removing the button combination. refers to a protocol capability where the user can issue a command from the standard Fastboot mode to forcibly reboot the device into EDL mode. fastboot edl v2