From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967159AbeEYQWN (ORCPT ); Fri, 25 May 2018 12:22:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:60558 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966854AbeEYQWM (ORCPT ); Fri, 25 May 2018 12:22:12 -0400 Date: Fri, 25 May 2018 18:21:54 +0200 From: Greg Kroah-Hartman To: Florian Schmaus Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH v6 0/3] driver-core: return EINVAL error instead of BUG_ON() Message-ID: <20180525162154.GA20197@kroah.com> References: <20180516160816.20251-1-flo@geekplace.eu> <20180523155913.29679-1-flo@geekplace.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180523155913.29679-1-flo@geekplace.eu> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 23, 2018 at 05:59:10PM +0200, Florian Schmaus wrote: > This patch series makes driver_register() emit an error message and > return a failure code instead of triggering a BUG_ON(). > > The first patch will cause driver_register() to fail gracefully if the > driver's bus was not initialized while printing out the name of the > faulty driver *and* the name of the involved bus. The second patch > records the error code if bus_register() fails. The third and final > patch of the series extends the first patch so that the recorded error > code is also print out if non-zero. Otherwise, if drv->bus->p is NULL > but the error code is zero, then probably bus_register() was never > called before. > > Greg questioned [1] whether [2/3] and [3/3] are necessary: > > > And really, when has this ever happened? Why would a bus registration > > fail and later allow a driver to be registered? > > I initially assumed that this is what cause me hitting the BUG_ON() > which [1/3] replaces: The bus registration failed and then the driver > attempts to register itself. But I did not had a chance to verify > that. I'll try to do so after my vacation. Meanwhile I hope that at > least [1/3] is considered an improvement of the kernel. If so, feel > free to pick it up. I've picked up patch 1, I don't think patches 2 or 3 are needed, due to the extreme unfrequency that this problem ever happens :) thanks, greg k-h