I define the start_up_server function as follow.
unsigned short start_up_server (void * p_device)
reg_value = 0x55;
printf("**reg_value = 0x%02x\n",reg_value);
Call the start_up_server in the main function. The printf function can't work normally.
**reg_value = 0x30f9
note: 30f9 is the address of the p_device.