This change definitely puts my driver into a headlock. I must call
cypress_write to set the control line within cypress_set_termios.
cypress_write locks several times when accessing the private data.
cypress_serial_control also must be called from within cypress_set_termios
which locks seve
2.6.9-rc3 changes the locking in the tty_ioctl.c function
change_termios(). It gets a spin_lock_irqsave(&tty_termios_lock,...)
before calling the tty driver's set_termios function.
This means that the drivers' set_termios functions cannot sleep.
Unfortunately, many USB serial drivers' set_termios
