#define LOS_ERRNO_MUX_PEND_IN_LOCK   LOS_ERRNO_OS_ERROR(LOS_MOD_MUX, 0x06)

Mutex error code: A thread locks a mutex after waiting for the mutex to be unlocked by another thread when the task scheduling is disabled.

Value: 0x02001d06

Solution: Check whether the task scheduling is disabled, or set uwtimeout to 0, which means that the thread will not wait for the mutex to become available.

在文件los_mux.h122行定义。