On Sat, 5 May 2018, Greg Kroah-Hartman wrote: > On Sun, May 06, 2018 at 11:47:52AM +1000, Finn Thain wrote: > > Loading a NuBus driver module on a non-NuBus machine triggers the > > BUG_ON(!drv->bus->p) in driver_register() because the bus does not get > > registered unless MACH_IS_MAC(). Avoid this by registering the bus > > unconditionally using postcore_initcall(). > > > > Cc: Greg Kroah-Hartman <[email protected]> > > Reported-by: Michael Schmitz <[email protected]> > > Tested-by: Stan Johnson <[email protected]> > > Fixes: 7f86c765a6a2 ("nubus: Add support for the driver model") > > Signed-off-by: Finn Thain <[email protected]> > > --- > > drivers/nubus/bus.c | 3 ++- > > drivers/nubus/nubus.c | 5 ----- > > include/linux/nubus.h | 1 - > > 3 files changed, 2 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/nubus/bus.c b/drivers/nubus/bus.c > > index d306c348c857..27ca9f1a281b 100644 > > --- a/drivers/nubus/bus.c > > +++ b/drivers/nubus/bus.c > > @@ -63,7 +63,7 @@ static struct device nubus_parent = { > > .init_name = "nubus", > > }; > > > > -int __init nubus_bus_register(void) > > +static int __init nubus_bus_register(void) > > { > > int err; > > > > @@ -78,6 +78,7 @@ int __init nubus_bus_register(void) > > device_unregister(&nubus_parent); > > return err; > > } > > +postcore_initcall(nubus_bus_register); > > Why not just have an "bus is registered" flag in your driver register > function that refuses to let drivers register with the driver core if it > isn't set?
Perhaps that should happen in the core driver_register() function. BUG_ON is frowned upon, after all. Would that be acceptable? I found a few drivers that set a flag the way you describe, which could then be simplified. But that pattern is rare. Most buses use the postcore_initcall() pattern, and so my patch took the conventional approach. > And then fix your linking error, the bus should come first in link > order, before your drivers :) > I didn't encounter any errors. How shall I reproduce this? Thanks. -- > thanks, > > greg k-h
