From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 16 May 2018 18:35:34 +0200 From: Greg Kroah-Hartman To: Florian Schmaus Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 1/3] driver-core: return EINVAL error instead of BUG_ON() Message-ID: <20180516163534.GB20425@kroah.com> References: <20180516120527.29403-1-flo@geekplace.eu> <20180516160816.20251-2-flo@geekplace.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180516160816.20251-2-flo@geekplace.eu> User-Agent: Mutt/1.9.5 (2018-04-13) X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Wed, May 16, 2018 at 06:08:14PM +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 > --- > > Notes: > - Do not split long strings across lines. > > 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..16b81d1c6cb7 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 it was not initialized.\n", The bus is not initialized, not the driver, right? This kind of makes it sound the other way around :( thanks, greg k-h