From c2872486ecdbb9e151eef60bdfca0382ba57acda Mon Sep 17 00:00:00 2001
From: Adrien Destugues <pulkomandy@gmail.com>
Date: Wed, 3 Dec 2014 13:18:47 +0100
Subject: [PATCH] Reset PS/2 devices before probing as synaptics touchpad.

Patch from dukscry, fixes #8616.
---
 src/add-ons/kernel/bus_managers/ps2/ps2_synaptics.cpp | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/src/add-ons/kernel/bus_managers/ps2/ps2_synaptics.cpp b/src/add-ons/kernel/bus_managers/ps2/ps2_synaptics.cpp
index 06232fef04..cba23a3f07 100644
--- a/src/add-ons/kernel/bus_managers/ps2/ps2_synaptics.cpp
+++ b/src/add-ons/kernel/bus_managers/ps2/ps2_synaptics.cpp
@@ -57,6 +57,7 @@ send_touchpad_arg_timeout(ps2_dev *dev, uint8 arg, bigtime_t timeout)
 {
 	int8 i;
 	uint8 val[8];
+
 	for (i = 0; i < 4; i++) {
 		val[2 * i] = (arg >> (6 - 2 * i)) & 3;
 		val[2 * i + 1] = 0xE8;
@@ -280,6 +281,15 @@ probe_synaptics(ps2_dev *dev)
 	status_t status;
 	TRACE("SYNAPTICS: probe\n");
 
+	// We reset the device here because it may have been left in a confused
+	// state by a previous probing attempt. Some synaptics touchpads are known
+	// to lockup when we attempt to detect them as IBM trackoints.
+	ps2_reset_mouse(dev);
+
+	// And after resetting we must wait a little for the device to become ready
+	// again...
+	snooze(400000);
+
 	status = send_touchpad_arg(dev, 0x00);
 	if (status != B_OK)
 		return status;