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 7399FC43603 for ; Tue, 10 Dec 2019 22:32:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 471C1214AF for ; Tue, 10 Dec 2019 22:32:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576017144; bh=x3aG7lm2+c8CM6MgbuvFVGF/tQTmsmjJE5Xxk9vXbg4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jut02Yh/S230CtMXcbpNxOQ1KKHRbhRVeINeN+EMuHUABcZjXKBvDZrji6e73Pgkh dVddkYOgzCyzWw2bW2pd2svnQHS8piDYDDXRISWYFtedUkFZhkqLfdUozMqQpPz4Qz 8k5YUC3TX0zBoDGLQeIkQNaYaPwlUnN4RJsSHE2g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729438AbfLJWcX (ORCPT ); Tue, 10 Dec 2019 17:32:23 -0500 Received: from mail.kernel.org ([198.145.29.99]:52266 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728415AbfLJWcB (ORCPT ); Tue, 10 Dec 2019 17:32:01 -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 15CB420828; Tue, 10 Dec 2019 22:32:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576017120; bh=x3aG7lm2+c8CM6MgbuvFVGF/tQTmsmjJE5Xxk9vXbg4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uOe66+B6kEKgo5sLFtCC+bq6fjBimDLmWWFXcYiDbJCxvevm3EB/v4ojI3AKm/+mh dH046yFgHsndzDrS6F0shMl/YNQqOGd76ITczYtFiEDI8wMld8jNMfHAh/C+MQ2Fxf oskfupvH198Tc8DKUiFVQDW6Dn+LZJwk7j4o1z64= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sudip Mukherjee , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH AUTOSEL 4.9 72/91] parport: load lowlevel driver if ports not found Date: Tue, 10 Dec 2019 17:30:16 -0500 Message-Id: <20191210223035.14270-72-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191210223035.14270-1-sashal@kernel.org> References: <20191210223035.14270-1-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 daa2eb3050df3..a7ceed7182acb 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