Hi Finn,
On Sun, May 6, 2018 at 3:47 AM, Finn Thain <[email protected]> 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);
nubus_bus_register() two things:
1. Register the NuBus parent device, which represents the bus host,
2. Register the NuBus bus, which represents the bus type.
I think this should be split in two, and only the latter should be done
regardless of the presence of NuBus host hardware, to fix the crash.
>
> static void nubus_device_release(struct device *dev)
> {
> diff --git a/drivers/nubus/nubus.c b/drivers/nubus/nubus.c
> index 4621ff98138c..f6bab483f4cb 100644
> --- a/drivers/nubus/nubus.c
> +++ b/drivers/nubus/nubus.c
> @@ -869,15 +869,10 @@ static void __init nubus_scan_bus(void)
>
> static int __init nubus_init(void)
> {
> - int err;
> -
> if (!MACH_IS_MAC)
> return 0;
>
> nubus_proc_init();
> - err = nubus_bus_register();
> - if (err)
> - return err;
Hence you should still register the NuBus parent device here.
> nubus_scan_bus();
> return 0;
> }
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email protected]
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
