Commit 05ce3e53 authored Mar 27, 2020 by Cornelia Huck Committed by Vasily Gorbik Apr 06, 2020

s390/cio: avoid duplicated 'ADD' uevents



The common I/O layer delays the ADD uevent for subchannels and
delegates generating this uevent to the individual subchannel
drivers. The io_subchannel driver will do so when the associated
ccw_device has been registered -- but unconditionally, so more
ADD uevents will be generated if a subchannel has been unbound
from the io_subchannel driver and later rebound.

To fix this, only generate the ADD event if uevents were still
suppressed for the device.

Fixes: fa1a8c23 ("s390: cio: Delay uevents for subchannels")
Message-Id: <20200327124503.9794-2-cohuck@redhat.com>
Reported-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Boris Fiuczynski <fiuczy@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

parent 9c159bbc

drivers/s390/cio/device.c

+9 −4

Original line number	Diff line number	Diff line
		@@ -849,8 +849,10 @@ static void io_subchannel_register(struct ccw_device *cdev)
		* Now we know this subchannel will stay, we can throw
		* our delayed uevent.
		*/
		if (dev_get_uevent_suppress(&sch->dev)) {
		dev_set_uevent_suppress(&sch->dev, 0);
		kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
		}
		/* make it known to the system */
		ret = ccw_device_add(cdev);
		if (ret) {
		@@ -1058,8 +1060,11 @@ static int io_subchannel_probe(struct subchannel *sch)
		* Throw the delayed uevent for the subchannel, register
		* the ccw_device and exit.
		*/
		if (dev_get_uevent_suppress(&sch->dev)) {
		/* should always be the case for the console */
		dev_set_uevent_suppress(&sch->dev, 0);
		kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
		}
		cdev = sch_get_cdev(sch);
		rc = ccw_device_add(cdev);
		if (rc) {

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