Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754172AbaJJVCi (ORCPT ); Fri, 10 Oct 2014 17:02:38 -0400 Received: from mail-pd0-f175.google.com ([209.85.192.175]:55710 "EHLO mail-pd0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750810AbaJJVCg (ORCPT ); Fri, 10 Oct 2014 17:02:36 -0400 Date: Fri, 10 Oct 2014 14:02:31 -0700 From: Dmitry Torokhov To: Jiri Kosina Cc: linux-input@vger.kernel.org, Linus Torvalds , Vojtech Pavlik , Hans de Goede , linux-kernel@vger.kernel.org Subject: Re: [PATCH] Input: i8042 - disable active multiplexing by default Message-ID: <20141010210231.GA38320@dtor-ws> References: <20141010205131.GA3271@dtor-ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 10, 2014 at 10:59:19PM +0200, Jiri Kosina wrote: > On Fri, 10 Oct 2014, Dmitry Torokhov wrote: > > > Active multiplexing is a nice feature as it allows several pointing devices > > (such as touchpad and external mouse) use their native protocols at the > > same time. Unfortunately many manufacturers do not implement the feature > > properly even though they advertise it. The problematic implementations are > > never fixed, since Windows by default does not use this mode, and move from > > one BIOS/model of laptop to another. When active multiplexing is broken > > turning it on usually results in touchpad, keyboard, or both unresponsive. > > > > With PS/2 usage on decline (most of PS/2 devices in use nowadays are > > internal laptop touchpads), I expect number of users who have laptops with > > working MUX implementation, docking stations with external PS/2 ports, and > > who are still using external PS/2 mice, to be rather small. Let's flip the > > default to be OFF and allow activating it through i8042.nomux=0 kernel > > option. We'll also keep DMI table where we can record known good models. > > Being responsible for introducing a non-trivial portion of > i8042_dmi_nomux_table[] entries: > > Acked-by: Jiri Kosina > > If nothing else, it'd make my life easier :) > > [ ... snip ... ] > > diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c > > index f5a98af..9a97c2b 100644 > > --- a/drivers/input/serio/i8042.c > > +++ b/drivers/input/serio/i8042.c > > @@ -39,7 +39,7 @@ static bool i8042_noaux; > > module_param_named(noaux, i8042_noaux, bool, 0); > > MODULE_PARM_DESC(noaux, "Do not probe or use AUX (mouse) port."); > > > > -static bool i8042_nomux; > > +static bool i8042_nomux = true; > > Hmmm ... perhaps if we want to be really friendly, we should warn (and I > definitely don't mean WARN(), but rather pr_info() or something) if we > encounter that the cmdline contains 'i8042.nomux=1'. Warn about what? That they do not need this option anymore? They might if they downgrade the kernel. I would not bother... Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/