From 87685a78e83f990705b7eeb5b3afb3045a8da5ce Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Fri, 21 Feb 2014 10:31:44 +0100
Subject: [PATCH synaptics 08/11] Wait for *new* coordinates on a clickpad
click before reporting the click
It is possible for a click to get reported before any related touch events
get reported, here is the relevant part of an evemu-record session on a T440s:
E: 3.985585 0000 0000 0000 # ------------ SYN_REPORT (0) ----------
E: 3.997419 0003 0039 -001 # EV_ABS / ABS_MT_TRACKING_ID -1
E: 3.997419 0001 014a 0000 # EV_KEY / BTN_TOUCH 0
E: 3.997419 0003 0018 0000 # EV_ABS / ABS_PRESSURE 0
E: 3.997419 0001 0145 0000 # EV_KEY / BTN_TOOL_FINGER 0
E: 3.997419 0000 0000 0000 # ------------ SYN_REPORT (0) ----------
E: 5.117881 0001 0110 0001 # EV_KEY / BTN_LEFT 1
E: 5.117881 0000 0000 0000 # ------------ SYN_REPORT (0) ----------
E: 5.133422 0003 0039 0187 # EV_ABS / ABS_MT_TRACKING_ID 187
E: 5.133422 0003 0035 3098 # EV_ABS / ABS_MT_POSITION_X 3098
E: 5.133422 0003 0036 3282 # EV_ABS / ABS_MT_POSITION_Y 3282
E: 5.133422 0003 003a 0046 # EV_ABS / ABS_MT_PRESSURE 46
E: 5.133422 0001 014a 0001 # EV_KEY / BTN_TOUCH 1
E: 5.133422 0003 0000 3102 # EV_ABS / ABS_X 3102
E: 5.133422 0003 0001 3282 # EV_ABS / ABS_Y 3282
E: 5.133422 0003 0018 0046 # EV_ABS / ABS_PRESSURE 46
E: 5.133422 0001 0145 0001 # EV_KEY / BTN_TOOL_FINGER 1
E: 5.133422 0000 0000 0000 # ------------ SYN_REPORT (0) ----------
Notice the BTN_LEFT event all by itself!
If this happens, it may lead to the following problem scenario:
-touch the touchpad in its right click area
-let go of the touchpad
-rapidly click in the middle area, so that BTN_LEFT gets reported before the
new coordinates (such as seen in the trace above, this may require some
practicing with evemu-record to reproduce)
-the driver registers the click as a right click because it uses the
old coordinates from the cumulative coordinates to determine the
click location
This commit fixes this by:
1) Resetting the cumulative coordinates not only when no button is pressed,
but also when there is no finger touching the touchpad, so that when
we do get a touch the cumulative coordinates start at the right place
2) Delaying processing the BTN_LEFT down transition if there is no finger
touching the touchpad
This approach has one downside, if we wrongly identify a touchpad as
a clickpad, then the left button won't work unless the user touches the
touchpad while clicking the left button.
If we want we can fix this by doing something like this:
1) Making update_hw_button_state return a delay; and
2) Tracking that we've delayed BTN_LEFT down transition processing; and
3) When we've delayed BTN_LEFT down transition return a small delay value; and
4) If when we're called again we still don't have a finger down, just
treat the click as a BTN_LEFT
But this is not worth the trouble IMHO, the proper thing to do in this
scenario is to fix the mis-identification of the touchpad as a clickpad.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
(cherry picked from commit bbe4c56c4998a90b478581a4d93717251d8e05be)
---
src/eventcomm.c | 5 +++--
src/synaptics.c | 7 +++++++
2 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/src/eventcomm.c b/src/eventcomm.c
index 8c30991..c5bc7ad 100644
--- a/src/eventcomm.c
+++ b/src/eventcomm.c
@@ -633,8 +633,9 @@ EventReadHwState(InputInfoPtr pInfo,
SynapticsResetTouchHwState(hw, FALSE);
- /* Reset cumulative values if buttons were not previously pressed */
- if (!hw->left && !hw->right && !hw->middle) {
+ /* Reset cumulative values if buttons were not previously pressed,
+ * or no finger was previously present. */
+ if ((!hw->left && !hw->right && !hw->middle) || hw->z < para->finger_low) {
hw->cumulative_dx = hw->x;
hw->cumulative_dy = hw->y;
sync_cumulative = TRUE;
diff --git a/src/synaptics.c b/src/synaptics.c
index 4cd45b6..1170963 100644
--- a/src/synaptics.c
+++ b/src/synaptics.c
@@ -2774,6 +2774,12 @@ update_hw_button_state(const InputInfoPtr pInfo, struct SynapticsHwState *hw,
if (para->clickpad) {
/* hw->left is down, but no other buttons were already down */
if (!(priv->lastButtons & 7) && hw->left && !hw->right && !hw->middle) {
+ /* If the finger down event is delayed, the x and y
+ * coordinates are stale so we delay processing the click */
+ if (hw->z < para->finger_low) {
+ hw->left = 0;
+ goto out;
+ }
if (is_inside_rightbutton_area(para, hw->x, hw->y)) {
hw->left = 0;
hw->right = 1;
@@ -2805,6 +2811,7 @@ update_hw_button_state(const InputInfoPtr pInfo, struct SynapticsHwState *hw,
if (hw->left && !(priv->lastButtons & 7) && hw->numFingers >= 1)
handle_clickfinger(priv, hw);
+out:
/* Two finger emulation */
if (hw->numFingers == 1 && hw->z >= para->emulate_twofinger_z &&
hw->fingerWidth >= para->emulate_twofinger_w) {
--
1.8.5.3