From: Cornelia Huck <cohuck@xxxxxxxxxx>
[ Upstream commit 05ce3e53f375295c2940390b2b429e506e07655c ]
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: fa1a8c23eb7d ("s390: cio: Delay uevents for subchannels")
Message-Id: <20200327124503.9794-2-cohuck@xxxxxxxxxx>
Reported-by: Boris Fiuczynski <fiuczy@xxxxxxxxxxxxx>
Reviewed-by: Peter Oberparleiter <oberpar@xxxxxxxxxxxxx>
Reviewed-by: Boris Fiuczynski <fiuczy@xxxxxxxxxxxxx>
Signed-off-by: Cornelia Huck <cohuck@xxxxxxxxxx>
Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/s390/cio/device.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 0c6245fc77069..983f9c9e08deb 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -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.
*/
- dev_set_uevent_suppress(&sch->dev, 0);
- kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
+ 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.
*/
- dev_set_uevent_suppress(&sch->dev, 0);
- kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
+ 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) {
--
2.20.1
