If the parport bus is not yet registered and any device using parallel port tries to register with the bus we get a stackdump with a message of Kernel bug. Reported-by: Fengguang Wu <fengguang.wu@xxxxxxxxx> Tested-by: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # 4.2+ Signed-off-by: Sudip Mukherjee <sudip.mukherjee@xxxxxxxxxxxxxxx> --- We should actually have some deferred probe here. But considering that you will be closing your trees soon so a quick fix to solve the problem for now. We will revisit this when we remove the old api (hopefully v4.7). drivers/parport/share.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/parport/share.c b/drivers/parport/share.c index 3308427..176b2b6 100644 --- a/drivers/parport/share.c +++ b/drivers/parport/share.c @@ -273,6 +273,9 @@ int __parport_register_driver(struct parport_driver *drv, struct module *owner, /* using device model */ int ret; + if (!parport_bus_type.p) + return -EAGAIN; + /* initialize common driver fields */ drv->driver.name = drv->name; drv->driver.bus = &parport_bus_type; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html