Linux tcgetattr followed by tcsetattr not working

Question

I need to save the terminal attributes (tcgetattr), set them to something that will block terminal echoing etc. (calling tcsetattr), and then later, after doing things with the framebuffer device /dev/fb0, restore the original attributes (calling tcsetattr).

I'm finding that the second call to tcsetattr always fails with an I/O error i.e. errno == EIO.

Is there a special trick to doing this?

struct termios originaltermios;
struct termios newtermios;
tcgetattr(console_fd, &originaltermios);
// 
newtermios = originaltermios;
tcsdrain(console_fd);
// (change newtermios here)
tcsetattr(console_fd, TCSANOW, &newtermios);
// ... do some stuff for 10-20 seconds with /dev/fd0
if (tcsetattr(console_fd, TCSANOW, &originaltermios)) {
    perror("tcsetattr"); // EIO
}
    new_termios.c_lflag &= ~ECHO;
    new_termios.c_lflag &= ~ISIG;
    new_termios.c_lflag &= ~ICANON;
    new_termios.c_lflag &= ~IEXTEN;
    new_termios.c_iflag &= ~ISTRIP;
    new_termios.c_iflag &= ~ICRNL;
    new_termios.c_iflag &= ~INLCR;
    new_termios.c_iflag &= ~IGNCR;
    new_termios.c_iflag &= ~BRKINT;
    new_termios.c_iflag &= ~(IXON|IXOFF);
    new_termios.c_cc[VMIN] = 0;
    new_termios.c_cc[VTIME] = 0;