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Commit 842d3fba authored by Stefan Bader's avatar Stefan Bader Committed by Linus Torvalds
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[PATCH] s390: tape retry flooding by deferred CC in interrupt 



If a deferred CC happens there will be lots of messages, because the retry is
done immediatly in the interrupt handler which can be too fast.  To avoid this
requeue the request and schedule the queue to be processed.

Signed-off-by: default avatarStefan Bader <shbader@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 20c64468

drivers/s390/char/tape_core.c

+5 −4
Original line number Diff line number Diff line
@@ -1064,15 +1064,16 @@ __tape_do_irq (struct ccw_device *cdev, unsigned long intparm, struct irb *irb) 
	/*

	 * If the condition code is not zero and the start function bit is

	 * still set, this is an deferred error and the last start I/O did

	 * not succeed. Restart the request now.

	 * not succeed. At this point the condition that caused the deferred

	 * error might still apply. So we just schedule the request to be

	 * started later.

	 */

	if (irb->scsw.cc != 0 && (irb->scsw.fctl & SCSW_FCTL_START_FUNC)) {

		PRINT_WARN("(%s): deferred cc=%i. restaring\n",

			cdev->dev.bus_id,

			irb->scsw.cc);

		rc = __tape_start_io(device, request);

		if (rc)

			__tape_end_request(device, request, rc);

		request->status = TAPE_REQUEST_QUEUED;

		schedule_work(&device->tape_dnr);

		return;

	}