On Thu, May 21, 2015 at 04:57:52PM +0800, Lu Baolu wrote: > ULPI registers its bus at module_init, so if the bus fails to register, the > module will fail to load and all will be well in the world. > > However, if the ULPI code is built-in rather than a module, the bus > initialization may fail, but we'd still try to register drivers later onto > a non-existent bus, which will panic the kernel. > > Fix that by checking that the bus was indeed initialized before trying to > register drivers on top of it. > > Signed-off-by: Sasha Levin <[email protected]> > Signed-off-by: Heikki Krogerus <[email protected]> > Signed-off-by: Lu Baolu <[email protected]> > Reported-by: Zhuo Qiuxu <[email protected]> > Reviewed-by: David Cohen <[email protected]> > --- > drivers/usb/common/ulpi.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c > index 0e6f968..af52b46 100644 > --- a/drivers/usb/common/ulpi.c > +++ b/drivers/usb/common/ulpi.c > @@ -132,6 +132,10 @@ int ulpi_register_driver(struct ulpi_driver *drv) > if (!drv->probe) > return -EINVAL; > > + /* Was the bus registered successfully? */ > + if (unlikely(WARN_ON(!ulpi_bus.p)))
never use unlikely/likely unless you can actually measure the difference if the marking is not used. Hint, on driver probe time, you can't. thanks, greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
