From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754278Ab1CQMS5 (ORCPT ); Thu, 17 Mar 2011 08:18:57 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:53068 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754118Ab1CQMSy (ORCPT ); Thu, 17 Mar 2011 08:18:54 -0400 Date: Thu, 17 Mar 2011 12:18:49 +0000 From: Alan Cox To: David Daney Cc: linux-serial@vger.kernel.org, gregkh@suse.de, linux-kernel@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, grant.likely@secretlab.ca Subject: Re: [RFC PATCH 1/2] serial: 8250: Add a notifier chain for driver registration. Message-ID: <20110317121849.49d7c425@lxorguk.ukuu.org.uk> In-Reply-To: <1300325167-26433-2-git-send-email-ddaney@caviumnetworks.com> References: <1300325167-26433-1-git-send-email-ddaney@caviumnetworks.com> <1300325167-26433-2-git-send-email-ddaney@caviumnetworks.com> X-Mailer: Claws Mail 3.7.8 (GTK+ 2.22.0; x86_64-redhat-linux-gnu) Face: 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 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 16 Mar 2011 18:26:06 -0700 David Daney wrote: > The 8250 driver is a bit weird in that in addition to supporting > platform devices, extra devices can be added by calling > serial8250_register_port(). > > The problem is that if we call serial8250_register_port() before the > driver is initialized Bad Things happen (we dereference NULL > pointers). > > There doesn't seem to be a general way to know if a driver has been > initialized I've had a bigger dig into this. I think the correct answer is probably "always go via platform devices or similar". That *is* the notifier in the kernel of today. serial8250_register_port ultimately should I think ultimatly become an internal helper. Alan