I triggerd the BUG_ON() in driver_register() when booting a domU Xen
domain. Since there was no contextual information logged, I needed to
attach kgdb to determine the culprit (the wmi-bmof driver in my
case). The BUG_ON() was added in commit f48f3febb2cb ("driver-core: do
not register a driver with bus_type not registered").Instead of running into a BUG_ON() we print an error message identifying the, likely faulty, driver but continue booting. Signed-off-by: Florian Schmaus <[email protected]> --- Notes: Make it clear in the error message that the bus was not initialized and *not* the driver. drivers/base/driver.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/base/driver.c b/drivers/base/driver.c index ba912558a510..857c8f1b876e 100644 --- a/drivers/base/driver.c +++ b/drivers/base/driver.c @@ -148,7 +148,11 @@ int driver_register(struct device_driver *drv) int ret; struct device_driver *other; - BUG_ON(!drv->bus->p); + if (!drv->bus->p) { + pr_err("Driver '%s' was unable to register with bus_type '%s' because the bus was not initialized.\n", + drv->name, drv->bus->name); + return -EINVAL; + } if ((drv->bus->probe && drv->probe) || (drv->bus->remove && drv->remove) || -- 2.16.1
