From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754168AbbEUKHc (ORCPT ); Thu, 21 May 2015 06:07:32 -0400 Received: from mga11.intel.com ([192.55.52.93]:43534 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751569AbbEUKHa (ORCPT ); Thu, 21 May 2015 06:07:30 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.13,468,1427785200"; d="scan'208";a="574767709" Message-ID: <555DAE5D.3030209@linux.intel.com> Date: Thu, 21 May 2015 18:07:25 +0800 From: "Lu, Baolu" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Heikki Krogerus , Greg Kroah-Hartman , Sasha Levin , David Cohen CC: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1] usb: ulpi: don't register drivers if bus doesn't exist References: <1432198672-384-1-git-send-email-baolu.lu@linux.intel.com> In-Reply-To: <1432198672-384-1-git-send-email-baolu.lu@linux.intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Heikki, Sasha and others, Please ignore this patch. I should not squash these two patches into one and sign it off behalf of other people. I apologize for this and I'm sorry if this lets you feel affronted. Thanks, Baolu On 05/21/2015 04:57 PM, 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 > Signed-off-by: Heikki Krogerus > Signed-off-by: Lu Baolu > Reported-by: Zhuo Qiuxu > Reviewed-by: David Cohen > --- > 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))) > + return -ENODEV; > + > drv->driver.bus = &ulpi_bus; > > return driver_register(&drv->driver); > @@ -242,7 +246,7 @@ static int __init ulpi_init(void) > { > return bus_register(&ulpi_bus); > } > -module_init(ulpi_init); > +subsys_initcall(ulpi_init); > > static void __exit ulpi_exit(void) > {