s390/cio: remove uevent suppress from cio driver

commit fa1a8c23eb7d ("s390: cio: Delay uevents for subchannels")
introduced suppression of uevents for a subchannel until after it is
clear that the subchannel would not be unregistered again
immediately. This was done to avoid uevents being generated for I/O
subchannels with no valid device, which can happen on LPAR.

However, this also has some drawbacks: All subchannel drivers need to
manually remove the uevent suppression and generate an ADD uevent as
soon as they are sure that the subchannel will stay around. This misses
out on all uevents that are not the initial ADD uevent that would be
generated while uevents are suppressed; for example, all subchannels
were missing the BIND uevent.

As uevents being generated even for I/O subchannels without an
operational device turned out to be not as bad as missing uevents and
complicating the code flow, let's remove uevent suppression for
subchannels.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
[cohuck@redhat.com: modified changelog]
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Link: https://lore.kernel.org/r/20211122103756.352463-2-vneethv@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

1 files changed, 0 insertions, 19 deletions

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index ce9e7517430f..fa8293335077 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -470,16 +470,6 @@ int css_register_subchannel(struct subchannel *sch)
 	if (sch->st == SUBCHANNEL_TYPE_IO)
 		sch->dev.type = &io_subchannel_type;
 
-	/*
-	 * We don't want to generate uevents for I/O subchannels that don't
-	 * have a working ccw device behind them since they will be
-	 * unregistered before they can be used anyway, so we delay the add
-	 * uevent until after device recognition was successful.
-	 * Note that we suppress the uevent for all subchannel types;
-	 * the subchannel driver can decide itself when it wants to inform
-	 * userspace of its existence.
-	 */
-	dev_set_uevent_suppress(&sch->dev, 1);
 	css_update_ssd_info(sch);
 	/* make it known to the system */
 	ret = css_sch_device_register(sch);
@@ -488,15 +478,6 @@ int css_register_subchannel(struct subchannel *sch)
 			      sch->schid.ssid, sch->schid.sch_no, ret);
 		return ret;
 	}
-	if (!sch->driver) {
-		/*
-		 * No driver matched. Generate the uevent now so that
-		 * a fitting driver module may be loaded based on the
-		 * modalias.
-		 */
-		dev_set_uevent_suppress(&sch->dev, 0);
-		kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
-	}
 	return ret;
 }