Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751213AbbEXObE (ORCPT ); Sun, 24 May 2015 10:31:04 -0400 Received: from mail-wi0-f173.google.com ([209.85.212.173]:36930 "EHLO mail-wi0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751072AbbEXOa7 (ORCPT ); Sun, 24 May 2015 10:30:59 -0400 MIME-Version: 1.0 In-Reply-To: <20150524080940.GA4033@sudip-PC> References: <1432150406-20550-1-git-send-email-sasha.levin@oracle.com> <20150524071948.GA20923@kroah.com> <20150524080940.GA4033@sudip-PC> Date: Sun, 24 May 2015 17:30:57 +0300 Message-ID: Subject: Re: [PATCH] usb: ulpi: don't register drivers if bus doesn't exist From: Tal Shorer To: Sudip Mukherjee Cc: Greg KH , Sasha Levin , Heikki Krogerus , USB list , "" , David Cohen , Felipe Balbi Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2507 Lines: 59 Why do we even need that? If you take patch that makes ulpi_init a subsys_initcall you won't have this problem, and no additional weird hacks and errors will be needed On Sun, May 24, 2015 at 11:09 AM, Sudip Mukherjee wrote: > On Sun, May 24, 2015 at 12:19:48AM -0700, Greg KH wrote: >> On Wed, May 20, 2015 at 03:33:26PM -0400, Sasha Levin wrote: >> > ULPI registers it's 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-existant 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 >> > --- >> > drivers/usb/common/ulpi.c | 4 ++++ >> > 1 file changed, 4 insertions(+) >> > >> > diff --git a/drivers/usb/common/ulpi.c b/drivers/usb/common/ulpi.c >> > index 0e6f968..0b0a5e7 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 (!ulpi_bus.p) >> > + return -ENODEV; >> >> Ick, no, don't go mucking around in the bus internals like this, that's >> not ok. You should either "know" the bus is registered, or something is >> really wrong with the design here. > can't we use a variable which can be initialized to 1 in ulpi_init() if > the bus registers successfully and later check that? > > regards > sudip >> >> greg k-h >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/ > -- > To unsubscribe from this list: send the line "unsubscribe linux-usb" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/