From: Alan Cox Instead of checking for the BKL in these methods, take it ourselves. That avoids propogating it into the serial drivers and we can then fix them later on. Signed-off-by: Alan Cox Cc: Russell King Signed-off-by: Andrew Morton --- drivers/serial/serial_core.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff -puN drivers/serial/serial_core.c~serial_core-prepare-for-bkl-push-down drivers/serial/serial_core.c --- a/drivers/serial/serial_core.c~serial_core-prepare-for-bkl-push-down +++ a/drivers/serial/serial_core.c @@ -914,14 +914,14 @@ static void uart_break_ctl(struct tty_st struct uart_state *state = tty->driver_data; struct uart_port *port = state->port; - BUG_ON(!kernel_locked()); - + lock_kernel(); mutex_lock(&state->mutex); if (port->type != PORT_UNKNOWN) port->ops->break_ctl(port, break_state); mutex_unlock(&state->mutex); + unlock_kernel(); } static int uart_do_autoconfig(struct uart_state *state) @@ -1059,7 +1059,7 @@ static int uart_get_count(struct uart_st } /* - * Called via sys_ioctl under the BKL. We can use spin_lock_irq() here. + * Called via sys_ioctl. We can use spin_lock_irq() here. */ static int uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd, @@ -1069,8 +1069,8 @@ uart_ioctl(struct tty_struct *tty, struc void __user *uarg = (void __user *)arg; int ret = -ENOIOCTLCMD; - BUG_ON(!kernel_locked()); + lock_kernel(); /* * These ioctls don't rely on the hardware to be present. */ @@ -1143,6 +1143,7 @@ uart_ioctl(struct tty_struct *tty, struc out_up: mutex_unlock(&state->mutex); out: + unlock_kernel(); return ret; } @@ -1153,7 +1154,6 @@ static void uart_set_termios(struct tty_ unsigned long flags; unsigned int cflag = tty->termios->c_cflag; - BUG_ON(!kernel_locked()); /* * These are the bits that are used to setup various @@ -1165,9 +1165,11 @@ static void uart_set_termios(struct tty_ if ((cflag ^ old_termios->c_cflag) == 0 && tty->termios->c_ospeed == old_termios->c_ospeed && tty->termios->c_ispeed == old_termios->c_ispeed && - RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) + RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) { return; + } + lock_kernel(); uart_change_speed(state, old_termios); /* Handle transition to B0 status */ @@ -1200,7 +1202,7 @@ static void uart_set_termios(struct tty_ } spin_unlock_irqrestore(&state->port->lock, flags); } - + unlock_kernel(); #if 0 /* * No need to wake up processes in open wait, since they _