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Commit 26d766c6 authored by Martin Schwidefsky's avatar Martin Schwidefsky
Browse files

s390/3215: fix hanging console issue 



The ccw_device_start in raw3215_start_io can fail. raw3215_try_io
does not check if the request could be started and removes any
pending timer. This can leave the system in a hanging state.
Check for pending request after raw3215_start_io and start a
timer if necessary.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent e2213e04

drivers/s390/char/con3215.c

+17 −15
Original line number Diff line number Diff line
@@ -288,12 +288,16 @@ static void raw3215_timeout(unsigned long __data) 
	unsigned long flags;



	spin_lock_irqsave(get_ccwdev_lock(raw->cdev), flags);

	if (raw->flags & RAW3215_TIMER_RUNS) {

		del_timer(&raw->timer);

	raw->flags &= ~RAW3215_TIMER_RUNS;

	if (!(raw->port.flags & ASYNC_SUSPENDED)) {

		raw3215_mk_write_req(raw);

		raw3215_start_io(raw);

		if ((raw->queued_read || raw->queued_write) &&

		    !(raw->flags & RAW3215_WORKING) &&

		    !(raw->flags & RAW3215_TIMER_RUNS)) {

			raw->timer.expires = RAW3215_TIMEOUT + jiffies;

			add_timer(&raw->timer);

			raw->flags |= RAW3215_TIMER_RUNS;

		}

	}

	spin_unlock_irqrestore(get_ccwdev_lock(raw->cdev), flags);
@@ -317,18 +321,16 @@ static inline void raw3215_try_io(struct raw3215_info *raw) 
		    (raw->flags & RAW3215_FLUSHING)) {

			/* execute write requests bigger than minimum size */

			raw3215_start_io(raw);

			if (raw->flags & RAW3215_TIMER_RUNS) {

				del_timer(&raw->timer);

				raw->flags &= ~RAW3215_TIMER_RUNS;

		}

		} else if (!(raw->flags & RAW3215_TIMER_RUNS)) {

			/* delay small writes */

	}

	if ((raw->queued_read || raw->queued_write) &&

	    !(raw->flags & RAW3215_WORKING) &&

	    !(raw->flags & RAW3215_TIMER_RUNS)) {

		raw->timer.expires = RAW3215_TIMEOUT + jiffies;

		add_timer(&raw->timer);

		raw->flags |= RAW3215_TIMER_RUNS;

	}

}

}



/*

 * Call tty_wakeup from tasklet context