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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 B39B1C00454 for ; Tue, 10 Dec 2019 21:18:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 87D5A206D5 for ; Tue, 10 Dec 2019 21:18:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576012712; bh=/vREOKb9jodj8o9mPrlJrZrDr+M2BGghOsruvxTRfek=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=eYnvxLD1YU+CUZYFAf9CPzjetmzOKqRJkmJYKK7O+IvOIS8vxvvLajlTHJajWLj36 Gx2YcH0eZCmDyPkL/1hNAxwT6VCVHoElxZ0aV3z1sSOFoej5gWEqQw8AQ+N6cq1SRz 5Ryw5qWEPmSzUrpEt+y+XWwfr6QFxNwEthSwjq8E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727154AbfLJVMl (ORCPT ); Tue, 10 Dec 2019 16:12:41 -0500 Received: from mail.kernel.org ([198.145.29.99]:36562 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728973AbfLJVM2 (ORCPT ); Tue, 10 Dec 2019 16:12:28 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AAB38214AF; Tue, 10 Dec 2019 21:12:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576012348; bh=/vREOKb9jodj8o9mPrlJrZrDr+M2BGghOsruvxTRfek=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N2tfhTb1ZpIEwdlicpLthKa92E+Npwh+eUuBDpvqPdZwvXlWLgpikus5ZHLvzJxqU fdytjTwWdas1yfXHWhL6Gp/y/opKxsiGF2pzc9y1SOeFggC+YfIM8sQgilnx8GEqK3 gSDevFsBVxHi85XyOKmBAWniZe4m+cc2pye/X2R4= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sudip Mukherjee , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH AUTOSEL 5.4 278/350] parport: load lowlevel driver if ports not found Date: Tue, 10 Dec 2019 16:06:23 -0500 Message-Id: <20191210210735.9077-239-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191210210735.9077-1-sashal@kernel.org> References: <20191210210735.9077-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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 7b4ee33c19354..15c81cffd2de2 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