[S390] pm: io subchannel driver power management callbacks

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/drivers/s390/cio/device.c b/drivers/s390/cio/device.c
index 228a6c314d84..64bd79ac25a7 100644
--- a/drivers/s390/cio/device.c
+++ b/drivers/s390/cio/device.c
@@ -138,6 +138,19 @@ static struct css_device_id io_subchannel_ids[] = {
 };
 MODULE_DEVICE_TABLE(css, io_subchannel_ids);
 
+static int io_subchannel_prepare(struct subchannel *sch)
+{
+        struct ccw_device *cdev;
+        /*
+         * Don't allow suspend while a ccw device registration
+         * is still outstanding.
+         */
+        cdev = sch_get_cdev(sch);
+        if (cdev && !device_is_registered(&cdev->dev))
+                return -EAGAIN;
+        return 0;
+}
+
 static struct css_driver io_subchannel_driver = {
         .owner = THIS_MODULE,
         .subchannel_type = io_subchannel_ids,
@@ -148,6 +161,7 @@ static struct css_driver io_subchannel_driver = {
         .probe = io_subchannel_probe,
         .remove = io_subchannel_remove,
         .shutdown = io_subchannel_shutdown,
+        .prepare = io_subchannel_prepare,
 };
 
 struct workqueue_struct *ccw_device_work;