[PATCH 5.4 029/168] s390/cio: generate delayed uevent for vfio-ccw subchannels

[Greg Kroah-Hartman]

From: Cornelia Huck <cohuck@xxxxxxxxxx>

[ Upstream commit 2bc55eaeb88d30accfc1b6ac2708d4e4b81ca260 ]

The common I/O layer delays the ADD uevent for subchannels and
delegates generating this uevent to the individual subchannel
drivers. The vfio-ccw I/O subchannel driver, however, did not
do that, and will not generate an ADD uevent for subchannels
that had not been bound to a different driver (or none at all,
which also triggers the uevent).

Generate the ADD uevent at the end of the probe function if
uevents were still suppressed for the device.

Message-Id: <20200327124503.9794-3-cohuck@xxxxxxxxxx>
Fixes: 63f1934d562d ("vfio: ccw: basic implementation for vfio_ccw driver")
Reviewed-by: Eric Farman <farman@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/vfio_ccw_drv.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index e401a3d0aa570..339a6bc0339b0 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -167,6 +167,11 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
 	if (ret)
 		goto out_disable;
 
+	if (dev_get_uevent_suppress(&sch->dev)) {
+		dev_set_uevent_suppress(&sch->dev, 0);
+		kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
+	}
+
 	VFIO_CCW_MSG_EVENT(4, "bound to subchannel %x.%x.%04x\n",
 			   sch->schid.cssid, sch->schid.ssid,
 			   sch->schid.sch_no);
-- 
2.20.1