Commit ee31b337 authored by Russell King's avatar Russell King Committed by Russell King
Browse files

[SERIAL] Fix Bug 4900: S3 resume oops with irattach - Thinkpad A21m 



If we fail to re-startup a serial port on resume, shut it down
immediately and mark it as an error condition.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 270c7a72

drivers/serial/serial_core.c

+49 −35
Original line number Diff line number Diff line
@@ -209,8 +209,14 @@ static void uart_shutdown(struct uart_state *state) 
	struct uart_info *info = state->info;

	struct uart_port *port = state->port;



	if (!(info->flags & UIF_INITIALIZED))

		return;

	/*

	 * Set the TTY IO error marker

	 */

	if (info->tty)

		set_bit(TTY_IO_ERROR, &info->tty->flags);



	if (info->flags & UIF_INITIALIZED) {

		info->flags &= ~UIF_INITIALIZED;



		/*

		 * Turn off DTR and RTS early.
@@ -236,6 +242,12 @@ static void uart_shutdown(struct uart_state *state) 
		 * Ensure that the IRQ handler isn't running on another CPU.

		 */

		synchronize_irq(port->irq);

	}



	/*

	 * kill off our tasklet

	 */

	tasklet_kill(&info->tlet);



	/*

	 * Free the transmit buffer page.
@@ -244,15 +256,6 @@ static void uart_shutdown(struct uart_state *state) 
		free_page((unsigned long)info->xmit.buf);

		info->xmit.buf = NULL;

	}



	/*

	 * kill off our tasklet

	 */

	tasklet_kill(&info->tlet);

	if (info->tty)

		set_bit(TTY_IO_ERROR, &info->tty->flags);



	info->flags &= ~UIF_INITIALIZED;

}



/**
@@ -1928,14 +1931,25 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *port) 


	if (state->info && state->info->flags & UIF_INITIALIZED) {

		struct uart_ops *ops = port->ops;

		int ret;



		ops->set_mctrl(port, 0);

		ops->startup(port);

		ret = ops->startup(port);

		if (ret == 0) {

			uart_change_speed(state, NULL);

			spin_lock_irq(&port->lock);

			ops->set_mctrl(port, port->mctrl);

			ops->start_tx(port);

			spin_unlock_irq(&port->lock);

		} else {

			/*

			 * Failed to resume - maybe hardware went away?

			 * Clear the "initialized" flag so we won't try

			 * to call the low level drivers shutdown method.

			 */

			state->info->flags &= ~UIF_INITIALIZED;

			uart_shutdown(state);

		}

	}



	up(&state->sem);