因未知原因读取串口

I am trying to interface a contact-less smart card reader over UART (usbserial) using termios framework under Linux. The code works fine on the PC, but when I cross-compile and try it out on an ARM9 target, it is able to open the device and even writing the command to the device, but the read command blocks indefinitely. Here is the code snippet :I am trying to interface a contact-less smart c