On Tue, May 15, 2018 at 03:51:12PM +0200, Florian Schmaus wrote:
> 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 <f...@geekplace.eu>
> ---
>
> Notes:
> - return EINVAL (instead of EBUSY)
> - follow common pattern when quoting commits in commit messages
>
> 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..afd5b08b7677 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) {
> + printk(KERN_ERR "Driver '%s' was unable to register bus_type\n",
> + drv->name);
checkpatch.pl should have said to use pr_err(), right? :)
Also, why not print out the driver name as well?
thanks,
greg k-h
