I have used an APi called "usb_control_msg " that comes under libusb(file name linux.c).Inside that Api one Ioctl Api is also used.When ever we removed USB device(PTP device) from the board,the above mentioned APi will get executed and Ioctl will return with a netive value and -19 is getting as return value of usb_control_msg API.and we try to execute perror ("err: usb_USB_REQ_GET_STATUS") if return of usb_control_msg < 0.so whenver we try to execute perror statement.I got segmentation fault.Can anyone tell what maybe the root cause of the above problem