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Commit 55fb7347 authored by Sebastian Ott's avatar Sebastian Ott Committed by Martin Schwidefsky
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s390/cio: recover from bad paths 



In some situations we don't receive notification from firmware that
a previously unusable channelpath is usable again.

Schedule recovery for devices that return from path verification
without using all potentially usable paths. The recovery thread will
periodically trigger a path verification on the affected devices.

Signed-off-by: default avatarSebastian Ott <sebott@linux.vnet.ibm.com>
Suggested-by: default avatarPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: default avatarPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent c8b85024

drivers/s390/cio/device.c

+9 −3
Original line number Diff line number Diff line
@@ -1225,10 +1225,16 @@ static int device_is_disconnected(struct ccw_device *cdev) 
static int recovery_check(struct device *dev, void *data)

{

	struct ccw_device *cdev = to_ccwdev(dev);

	struct subchannel *sch;

	int *redo = data;



	spin_lock_irq(cdev->ccwlock);

	switch (cdev->private->state) {

	case DEV_STATE_ONLINE:

		sch = to_subchannel(cdev->dev.parent);

		if ((sch->schib.pmcw.pam & sch->opm) == sch->vpm)

			break;

		/* fall through */

	case DEV_STATE_DISCONNECTED:

		CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",

			      cdev->private->dev_id.ssid,
@@ -1260,7 +1266,7 @@ static void recovery_work_func(struct work_struct *unused) 
		}

		spin_unlock_irq(&recovery_lock);

	} else

		CIO_MSG_EVENT(4, "recovery: end\n");

		CIO_MSG_EVENT(3, "recovery: end\n");

}



static DECLARE_WORK(recovery_work, recovery_work_func);
@@ -1274,11 +1280,11 @@ static void recovery_func(unsigned long data) 
	schedule_work(&recovery_work);

}



static void ccw_device_schedule_recovery(void)

void ccw_device_schedule_recovery(void)

{

	unsigned long flags;



	CIO_MSG_EVENT(4, "recovery: schedule\n");

	CIO_MSG_EVENT(3, "recovery: schedule\n");

	spin_lock_irqsave(&recovery_lock, flags);

	if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {

		recovery_phase = 0;

drivers/s390/cio/device.h

+1 −0
Original line number Diff line number Diff line
@@ -134,6 +134,7 @@ void ccw_device_set_disconnected(struct ccw_device *cdev); 
void ccw_device_set_notoper(struct ccw_device *cdev);



void ccw_device_set_timeout(struct ccw_device *, int);

void ccw_device_schedule_recovery(void);



/* Channel measurement facility related */

void retry_set_schib(struct ccw_device *cdev);

drivers/s390/cio/device_fsm.c

+12 −0
Original line number Diff line number Diff line
@@ -476,6 +476,17 @@ static void create_fake_irb(struct irb *irb, int type) 
	}

}



static void ccw_device_handle_broken_paths(struct ccw_device *cdev)

{

	struct subchannel *sch = to_subchannel(cdev->dev.parent);

	u8 broken_paths = (sch->schib.pmcw.pam & sch->opm) ^ sch->vpm;



	if (broken_paths && (cdev->private->path_broken_mask != broken_paths))

		ccw_device_schedule_recovery();



	cdev->private->path_broken_mask = broken_paths;

}



void ccw_device_verify_done(struct ccw_device *cdev, int err)

{

	struct subchannel *sch;
@@ -508,6 +519,7 @@ void ccw_device_verify_done(struct ccw_device *cdev, int err) 
			memset(&cdev->private->irb, 0, sizeof(struct irb));

		}

		ccw_device_report_path_events(cdev);

		ccw_device_handle_broken_paths(cdev);

		break;

	case -ETIME:

	case -EUSERS:

drivers/s390/cio/io_sch.h

+2 −0
Original line number Diff line number Diff line
@@ -131,6 +131,8 @@ struct ccw_device_private { 
				   not operable */

	u8 path_gone_mask;	/* mask of paths, that became unavailable */

	u8 path_new_mask;	/* mask of paths, that became available */

	u8 path_broken_mask;	/* mask of paths, which were found to be

				   unusable */

	struct {

		unsigned int fast:1;	/* post with "channel end" */

		unsigned int repall:1;	/* report every interrupt status */