From patchwork Tue Sep 1 07:56:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans de Goede X-Patchwork-Id: 11747587 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CC77C109B for ; Tue, 1 Sep 2020 07:56:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B0EAA2078B for ; Tue, 1 Sep 2020 07:56:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="XnPBd9g7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727099AbgIAH4b (ORCPT ); Tue, 1 Sep 2020 03:56:31 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:39366 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727075AbgIAH4a (ORCPT ); Tue, 1 Sep 2020 03:56:30 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1598946988; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=4tIWuRI0CI9BjMSRluT5gYGTUqtjzTGhEGG4awnur2Q=; b=XnPBd9g7nPiWfXqXu9ZrI2O0EV3T/YreHAP4ISkkeNqaXEywHIqHK8+3n5kmMg0r6dckLh wzBrFTHGlTnhj2I8Zjd8rj3E/UU1nMx7F6aKs5Os1ew4tR/k6SXVWakxtJak6lMdI47JNd TJKiEyVrWQS3NudAFBgxogNnrP+PGGY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-165-36Ou7Wl8PPmymP1Z2xj3Yg-1; Tue, 01 Sep 2020 03:56:24 -0400 X-MC-Unique: 36Ou7Wl8PPmymP1Z2xj3Yg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D194A80EF8C; Tue, 1 Sep 2020 07:56:23 +0000 (UTC) Received: from x1.localdomain.com (ovpn-114-149.ams2.redhat.com [10.36.114.149]) by smtp.corp.redhat.com (Postfix) with ESMTP id AC5FC19C4F; Tue, 1 Sep 2020 07:56:22 +0000 (UTC) From: Hans de Goede To: Dmitry Torokhov Cc: Hans de Goede , linux-input@vger.kernel.org, Marius Iacob Subject: [PATCH] Input: i8042 - Allow insmod to succeed on devices without an i8042 controller Date: Tue, 1 Sep 2020 09:56:21 +0200 Message-Id: <20200901075621.4580-1-hdegoede@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org The i8042 module exports several symbols which may be used by other modules. Before this commit it would refuse to load (when built as a module itself) on systems without an i8042 controller. This is a problem specifically for the asus-nb-wmi module. Many Asus laptops support the Asus WMI interface. Some of them have an i8042 controller and need to use i8042_install_filter() to filter some kbd events. Other models do not have an i8042 controller (e.g. they use an USB attached kbd). Before this commit the asus-nb-wmi driver could not be loaded on Asus models without an i8042 controller, when the i8042 code was built as a module (as Arch Linux does) because the module_init function of the i8042 module would fail with -ENODEV and thus the i8042_install_filter symbol could not be loaded. This commit fixes this by exiting from module_init with a return code of 0 if no controller is found. It also adds a i8042_present bool to make the module_exit function a no-op in this case and also adds a check for i8042_present to the exported i8042_command function. The latter i8042_present check should not really be necessary because when builtin that function can already be used on systems without an i8042 controller, but better safe then sorry. Reported-and-tested-by: Marius Iacob Signed-off-by: Hans de Goede --- drivers/input/serio/i8042.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c index d3eda48032e3..944cbb519c6d 100644 --- a/drivers/input/serio/i8042.c +++ b/drivers/input/serio/i8042.c @@ -122,6 +122,7 @@ module_param_named(unmask_kbd_data, i8042_unmask_kbd_data, bool, 0600); MODULE_PARM_DESC(unmask_kbd_data, "Unconditional enable (may reveal sensitive data) of normally sanitize-filtered kbd data traffic debug log [pre-condition: i8042.debug=1 enabled]"); #endif +static bool i8042_present; static bool i8042_bypass_aux_irq_test; static char i8042_kbd_firmware_id[128]; static char i8042_aux_firmware_id[128]; @@ -343,6 +344,9 @@ int i8042_command(unsigned char *param, int command) unsigned long flags; int retval; + if (!i8042_present) + return -1; + spin_lock_irqsave(&i8042_lock, flags); retval = __i8042_command(param, command); spin_unlock_irqrestore(&i8042_lock, flags); @@ -1612,12 +1616,15 @@ static int __init i8042_init(void) err = i8042_platform_init(); if (err) - return err; + return (err == -ENODEV) ? 0 : err; err = i8042_controller_check(); if (err) goto err_platform_exit; + /* Set this before creating the dev to allow i8042_command to work right away */ + i8042_present = true; + pdev = platform_create_bundle(&i8042_driver, i8042_probe, NULL, 0, NULL, 0); if (IS_ERR(pdev)) { err = PTR_ERR(pdev); @@ -1636,6 +1643,9 @@ static int __init i8042_init(void) static void __exit i8042_exit(void) { + if (!i8042_present) + return; + platform_device_unregister(i8042_platform_device); platform_driver_unregister(&i8042_driver); i8042_platform_exit();