Arch Linux

HAL has a latent bug that prevents an ALPS touchpad from being recognized by Xorg; however, the DualPoint (mouse nipple) still works.

This bug may never be a problem, given that HAL has been deprecated and may not even be in use by the time Linux 2.6.33 becomes part of Arch Linux; however, it may be worthwhile to describe a/the solution here.

In order to fix the problem, either the end user can patch an installed file as follows:

patch /usr/share/hal/fdi/policy/10osvendor/10-x11-input.fdi bug-1/solution/hal-touchpad-evdev.patch

or the `hal' package can be rebuilt by applying `bug-1/solution/PKGBUILD.patch' to the hal package's PKGBUILD and then including `bug-1/solution/hal-touchpad-evdev.patch' among the other patches that are shipped with the hal package's PKGBUILD.

(Currently, the hal package won't build; apply the PKGBUILD.patch from this bug report and THEN apply a solution from http://bugs.archlinux.org/task/17719).

The following description and (modified) attached patch came from:

http://lists.freedesktop.org/archives/hal/2010-January/013734.html

(sorry if the formatting isn't as nice in this bug report)

From 4bd49edaa11926c885dccb60d2b2df231488d7d4 Mon Sep 17 00:00:00 2001
From: Michael Witten <mfwitten@gmail.com>
Date: Tue, 5 Jan 2010 16:24:17 -0600
Subject: [PATCH] Policy: handle `input.touchpad' explicitly

This commit essentially duplicates the policy for:

<match key="info.capabilities" contains="input.mouse">

and then changes `input.mouse' to `input.touchpad'. This
is necessary because in Linus Torvalds's Linux repo:

git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git

the following commit:

commit 7105d2ea73e1391b681d0e1212c42f561c64d429
Author: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: Fri Dec 11 23:54:54 2009 -0800

Input: ALPS - do not set REL_X/REL_Y capabilities on the touchpad

Relative events are only reported via secondary device therefore device
associated with the touchpad should not advertise these capabilities.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

made these few changes:

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index a3f492a..b03e7e0 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -487,6 +487,17 @@ int alps_init(struct psmouse *psmouse)
if (alps_hw_init(psmouse))
goto init_fail;

+ /*
+ * Undo part of setup done for us by psmouse core since touchpad
+ * is not a relative device.
+ */
+ __clear_bit(EV_REL, dev1->evbit);
+ __clear_bit(REL_X, dev1->relbit);
+ __clear_bit(REL_Y, dev1->relbit);
+
+ /*
+ * Now set up our capabilities.
+ */
dev1->evbit[BIT_WORD(EV_KEY)] |= BIT_MASK(EV_KEY);
dev1->keybit[BIT_WORD(BTN_TOUCH)] |= BIT_MASK(BTN_TOUCH);
dev1->keybit[BIT_WORD(BTN_TOOL_FINGER)] |= BIT_MASK(BTN_TOOL_FINGER);

so that HAL no longer adds:

input.mouse

to an ALPS touchpad's:

info.capabilities

so that HAL no longer marks the ALPS touchpad with:

input.x11_driver = 'evdev'

because the policy file:

fdi/policy/10osvendor/10-x11-input.fdi

doesn't define the policy for:

<match key="info.capabilities" contains="input.touchpad">

which was previous unnecessary because everything used to
be caught by the policy for:

<match key="info.capabilities" contains="input.mouse">