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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 63B4EC2D0CE for ; Sun, 29 Dec 2019 17:33:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3F5A021744 for ; Sun, 29 Dec 2019 17:33:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577640836; bh=u1vbAAODFFibUTO2yMqM38STXoTtYukUrreTORXp/oo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zngSPAytutNWu168zlrEKvodruJQWbl6CA5qk9fazk/MFfohE501vbRhBuEX0DPXX kw0NBhUe+Mk96rU+FVfVwBNbQAQKW6lw03+SMm7eT4xdREm/S4iyXegEk/1udWbt6X HKKyqtl/h475cPbnMT0fx8YualhaQGjlsZl3Soqw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729545AbfL2Rdz (ORCPT ); Sun, 29 Dec 2019 12:33:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:36124 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729535AbfL2Rdu (ORCPT ); Sun, 29 Dec 2019 12:33:50 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 C7DD7207FF; Sun, 29 Dec 2019 17:33:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1577640830; bh=u1vbAAODFFibUTO2yMqM38STXoTtYukUrreTORXp/oo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ADZNhivx1NEo+i57OpjfSlRBMCk4oX+bW/Om6L2iLK/DWXN0o2a/ofEy4rOTz8sIN FtL3/cTXrfomjPpfLuusJKDNMzqOWh9wso5DOrrbogpfWhhUelYGaY1wRPwANPfMik 5SSqYIVXgTNMaWlkbFzaYHejFHd6+tM5Xpjpp5hE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sudip Mukherjee , Sasha Levin Subject: [PATCH 4.19 156/219] parport: load lowlevel driver if ports not found Date: Sun, 29 Dec 2019 18:19:18 +0100 Message-Id: <20191229162532.031849147@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191229162508.458551679@linuxfoundation.org> References: <20191229162508.458551679@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sudip Mukherjee [ Upstream commit 231ec2f24dad18d021b361045bbd618ba62a274e ] Usually all the distro will load the parport low level driver as part of their initialization. But we can get into a situation where all the parallel port drivers are built as module and we unload all the modules at a later time. Then if we just do "modprobe parport" it will only load the parport module and will not load the low level driver which will actually register the ports. So, check the bus if there is any parport registered, if not, load the low level driver. We can get into the above situation with all distro but only Suse has setup the alias for "parport_lowlevel" and so it only works in Suse. Users of Debian based distro will need to load the lowlevel module manually. Signed-off-by: Sudip Mukherjee Link: https://lore.kernel.org/r/20191016144540.18810-3-sudipm.mukherjee@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/parport/share.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/drivers/parport/share.c b/drivers/parport/share.c index 7b4ee33c1935..15c81cffd2de 100644 --- a/drivers/parport/share.c +++ b/drivers/parport/share.c @@ -230,6 +230,18 @@ static int port_check(struct device *dev, void *dev_drv) return 0; } +/* + * Iterates through all the devices connected to the bus and return 1 + * if the device is a parallel port. + */ + +static int port_detect(struct device *dev, void *dev_drv) +{ + if (is_parport(dev)) + return 1; + return 0; +} + /** * parport_register_driver - register a parallel port device driver * @drv: structure describing the driver @@ -282,6 +294,15 @@ int __parport_register_driver(struct parport_driver *drv, struct module *owner, if (ret) return ret; + /* + * check if bus has any parallel port registered, if + * none is found then load the lowlevel driver. + */ + ret = bus_for_each_dev(&parport_bus_type, NULL, NULL, + port_detect); + if (!ret) + get_lowlevel_driver(); + mutex_lock(®istration_lock); if (drv->match_port) bus_for_each_dev(&parport_bus_type, NULL, drv, -- 2.20.1