mpc52xx_uart_int and __uart_put_char both try to acquire the
port->lock. Therefore the function sequence of:
mpc52xx_uart_int--> ...-->flush_to_ldisc-->...-->__uart_put_char
can potentially trigger a deadlock. To avoid this deadlock a fix
similar to that found in the 8250.c serial driver is applied. The
deadlock is avoided by releasing the lock before pushing a buffer
and reacquiring it when completed.
Signed-off-by: Andrew Liu <shengping.liu@windriver.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Andrew Liu
fbe543b412