[RFC 1/1] s390/cio: Remove uevent-suppress from css driver

[Vineeth Vijayan <vneethv@linux.ibm.com>]

'commit fa1a8c23eb7d ("s390: cio: Delay uevents for subchannels")'
introduced the uevent suppression of subchannels. Even though there
are reasons for wanting to delay the uevent, it also introduces
problems. i.e On some platforms (qemu), where the udev-rule for the
subchannel needs to do driver_override to bind the vfio-ccw driver
instead of io_subchannel driver, but the suppressed uevent is
generated only when the device is found on the subchannel. By the
time it generates the uevent, it makes it difficult for the vfio-ccw
udev-rules to work.
This patch removes the uevent-suppress logic from the css driver.
The ADD uevent will be generated when there is a valid subchannel
and not after binding the valid device. The uevent generates while
device_add() during css_sch_device_register() function.

Signed-off-by: Vineeth Vijayan <vneethv@linux.ibm.com>
---
 drivers/s390/cio/chsc_sch.c     |  5 -----
 drivers/s390/cio/css.c          | 19 -------------------
 drivers/s390/cio/device.c       | 18 ------------------
 drivers/s390/cio/eadm_sch.c     |  5 -----
 drivers/s390/cio/vfio_ccw_drv.c |  5 -----
 5 files changed, 52 deletions(-)

diff --git a/drivers/s390/cio/chsc_sch.c b/drivers/s390/cio/chsc_sch.c
index 8f080d3fd380..b4057d781fb1 100644
--- a/drivers/s390/cio/chsc_sch.c
+++ b/drivers/s390/cio/chsc_sch.c
@@ -91,11 +91,6 @@ static int chsc_subchannel_probe(struct subchannel *sch)
 			 sch->schid.ssid, sch->schid.sch_no, ret);
 		dev_set_drvdata(&sch->dev, NULL);
 		kfree(private);
-	} else {
-		if (dev_get_uevent_suppress(&sch->dev)) {
-			dev_set_uevent_suppress(&sch->dev, 0);
-			kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
-		}
 	}
 	return ret;
 }
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index cca1a7c4bb33..6ebc0f7152e9 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -449,16 +449,6 @@ 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);
@@ -467,15 +457,6 @@ 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;
 }
 
diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index aab13c78db9f..363c9bbc4a24 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -845,14 +845,6 @@ static void io_subchannel_register(struct ccw_device *cdev)
 		adjust_init_count = 0;
 		goto out;
 	}
-	/*
-	 * 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) {
@@ -1055,16 +1047,6 @@ static int io_subchannel_probe(struct subchannel *sch)
 				      "attributes for subchannel "
 				      "0.%x.%04x (rc=%d)\n",
 				      sch->schid.ssid, sch->schid.sch_no, rc);
-		/*
-		 * The console subchannel already has an associated ccw_device.
-		 * 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) {
diff --git a/drivers/s390/cio/eadm_sch.c b/drivers/s390/cio/eadm_sch.c
index 53468ae64b99..f8b43583b487 100644
--- a/drivers/s390/cio/eadm_sch.c
+++ b/drivers/s390/cio/eadm_sch.c
@@ -243,11 +243,6 @@ static int eadm_subchannel_probe(struct subchannel *sch)
 	spin_lock_irq(&list_lock);
 	list_add(&private->head, &eadm_list);
 	spin_unlock_irq(&list_lock);
-
-	if (dev_get_uevent_suppress(&sch->dev)) {
-		dev_set_uevent_suppress(&sch->dev, 0);
-		kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
-	}
 out:
 	return ret;
 }
diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index 8c625b530035..7ccc5035c8fd 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -206,11 +206,6 @@ 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);
-- 
2.17.1