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Commit a6b93a90 authored by Russell King's avatar Russell King Committed by Russell King
Browse files

[SERIAL] Fix oops when removing suspended serial port 



A serial card might have been removed when the system is resumed.
This results in a suspended port being shut down, which results in
the ports shutdown method being called twice in a row.  This causes
BUGs.  Avoid this by tracking the suspended state separately from
the initialised state.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent fe59d537

drivers/serial/serial_core.c

+7 −2
Original line number Diff line number Diff line
@@ -1940,6 +1940,9 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *port) 
	if (state->info && state->info->flags & UIF_INITIALIZED) {

		const struct uart_ops *ops = port->ops;



		state->info->flags = (state->info->flags & ~UIF_INITIALIZED)

				     | UIF_SUSPENDED;



		spin_lock_irq(&port->lock);

		ops->stop_tx(port);

		ops->set_mctrl(port, 0);
@@ -2006,7 +2009,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *port) 
		console_start(port->cons);

	}



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

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

		const struct uart_ops *ops = port->ops;

		int ret;
@@ -2018,15 +2021,17 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *port) 
			ops->set_mctrl(port, port->mctrl);

			ops->start_tx(port);

			spin_unlock_irq(&port->lock);

			state->info->flags |= UIF_INITIALIZED;

		} 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);

		}



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

	}



	mutex_unlock(&state->mutex);

include/linux/serial_core.h

+1 −0
Original line number Diff line number Diff line
@@ -319,6 +319,7 @@ struct uart_info { 
#define UIF_CTS_FLOW		((__force uif_t) (1 << 26))

#define UIF_NORMAL_ACTIVE	((__force uif_t) (1 << 29))

#define UIF_INITIALIZED		((__force uif_t) (1 << 31))

#define UIF_SUSPENDED		((__force uif_t) (1 << 30))



	int			blocked_open;