Commit 89286320 authored Mar 21, 2018 by Julian Wiedmann Committed by Martin Schwidefsky Apr 10, 2018

s390/qdio: clear intparm during shutdown



During shutdown, qdio returns its ccw device back to control by the
upper-layer driver. But there is a remote chance that by the time where the
IRQ handler gets switched back, the interrupt for the preceding
ccw_device_{clear,halt} hasn't been presented yet.
Upper-layer drivers would then need to handle this IRQ - and since the IO
is issued with an intparm, it could very well be confused with whatever
intparm mechanism the driver uses itself (eg intparm == request address).

So when switching over the IRQ handler, also clear the intparm and have
upper-layer drivers deal with any such delayed interrupt as if it was
unsolicited.

Suggested-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

parent ab7efda4

drivers/s390/cio/qdio_main.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -1207,8 +1207,10 @@ int qdio_shutdown(struct ccw_device *cdev, int how)
		qdio_shutdown_thinint(irq_ptr);

		/* restore interrupt handler */
		if ((void )cdev->handler == (void )qdio_int_handler)
		if ((void )cdev->handler == (void )qdio_int_handler) {
		cdev->handler = irq_ptr->orig_handler;
		cdev->private->intparm = 0;
		}
		spin_unlock_irq(get_ccwdev_lock(cdev));

		qdio_set_state(irq_ptr, QDIO_IRQ_STATE_INACTIVE);