From: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx> The function ccw_device_unregister has to ensure to remove all references obtained by device_add and device_initialize. Unfortunately it gets called for devices which are 1) uninitialized, 2) initialized but unregistered, and 3) registered devices. To distinguish 1) and 2) this patch introduces a new flag "initialized", which is 1 as long as we hold the initial device reference. Signed-off-by: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx> Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx> --- drivers/s390/cio/device.c | 6 ++++++ drivers/s390/cio/io_sch.h | 1 + 2 files changed, 7 insertions(+) Index: quilt-2.6/drivers/s390/cio/device.c =================================================================== --- quilt-2.6.orig/drivers/s390/cio/device.c 2009-11-13 16:08:21.000000000 +0100 +++ quilt-2.6/drivers/s390/cio/device.c 2009-11-13 16:08:22.000000000 +0100 @@ -304,7 +304,11 @@ static void ccw_device_unregister(struct ccw_device *cdev) { if (device_is_registered(&cdev->dev)) { + /* Undo device_add(). */ device_del(&cdev->dev); + } + if (cdev->private->flags.initialized) { + cdev->private->flags.initialized = 0; /* Release reference from device_initialize(). */ put_device(&cdev->dev); } @@ -716,6 +720,7 @@ put_device(&cdev->dev); return -ENODEV; } + cdev->private->flags.initialized = 1; return 0; } @@ -998,6 +1003,7 @@ cdev = sch_get_cdev(sch); cdev->dev.groups = ccwdev_attr_groups; device_initialize(&cdev->dev); + cdev->private->flags.initialized = 1; ccw_device_register(cdev); /* * Check if the device is already online. If it is Index: quilt-2.6/drivers/s390/cio/io_sch.h =================================================================== --- quilt-2.6.orig/drivers/s390/cio/io_sch.h 2009-11-13 16:08:21.000000000 +0100 +++ quilt-2.6/drivers/s390/cio/io_sch.h 2009-11-13 16:08:22.000000000 +0100 @@ -167,6 +167,7 @@ unsigned int resuming:1; /* recognition while resume */ unsigned int pgroup:1; /* pathgroup is set up */ unsigned int mpath:1; /* multipathing is set up */ + unsigned int initialized:1; /* set if initial reference held */ } __attribute__((packed)) flags; unsigned long intparm; /* user interruption parameter */ struct qdio_irq *qdio_data; -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html