From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D232DC43381 for ; Mon, 25 Mar 2019 21:53:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A9DC82083D for ; Mon, 25 Mar 2019 21:53:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730212AbfCYVxl (ORCPT ); Mon, 25 Mar 2019 17:53:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:38920 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728912AbfCYVxk (ORCPT ); Mon, 25 Mar 2019 17:53:40 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BCF13206DF; Mon, 25 Mar 2019 21:53:39 +0000 (UTC) Date: Mon, 25 Mar 2019 17:53:38 -0400 From: Steven Rostedt To: Sudip Mukherjee Cc: Greg Kroah-Hartman , Linus Torvalds , linux-kernel@vger.kernel.org, Michal Kubecek Subject: Re: [PATCH] parport: daisy: do not try to load lowlevel driver Message-ID: <20190325175338.2fa290cc@gandalf.local.home> In-Reply-To: <20190325211325.21411-1-sudipm.mukherjee@gmail.com> References: <20190325211325.21411-1-sudipm.mukherjee@gmail.com> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 25 Mar 2019 21:13:25 +0000 Sudip Mukherjee wrote: > Some distros like Suse has an alias for "parport_lowlevel" and that > alias points to "parport_pc". Now when the parport bus registers, it > also initialises the daisy driver as the daisy driver is needed to > check the port when the port is first found. Due to the new device > model daisy driver will now try to find the parallel ports while trying > to register its driver so that it can bind with them. Now, since daisy > driver is loaded while parport bus is initialising the list of parport > is still empty and it tries to load the lowlevel driver, which has an > alias set to parport_pc, now causes a deadlock. > > We do not need to search for ports and bind the initial list of ports > to daisy driver as daisy driver is always the first driver to use the > new found parport and we know when the parport bus is registering the > list of parport will always be empty. So, proceed with the daisy_drv > registration even if the list of parport is empty. > > Fixes: 1aec4211204d ("parport: daisy: use new parport device model") > Reported-by: Michal Kubecek > Reported-by: Steven Rostedt > Tested-by: Michal Kubecek > Cc: Linus Torvalds > Signed-off-by: Sudip Mukherjee Tested-by: Steven Rostedt (VMware) -- Steve