[PATCH synaptics] eventcomm: Drop requirement for a grab during init

[Peter Hutterer]

When we required a grab on the device, this was a shortcut so we didn't have
to query the device only to realise we can't read events off it anyway. Now
that we don't actually grab the device by default, this is unnecessary.

Something else may have a temporary grab on the device during init, in which
case we just continue as usual and read events if and when they become
available.

Somewhat related to #77480.

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 src/eventcomm.c | 37 ++++++++++---------------------------
 1 file changed, 10 insertions(+), 27 deletions(-)

diff --git a/src/eventcomm.c b/src/eventcomm.c
index 3f9da7c..6e45d56 100644
--- a/src/eventcomm.c
+++ b/src/eventcomm.c
@@ -331,49 +331,33 @@ EventDeviceOffHook(InputInfoPtr pInfo)
  * - BTN_TOOL_PEN is _not_ set
  *
  * @param evdev Libevdev handle
- * @param test_grab If true, test whether an EVIOCGRAB is possible on the
- * device. A failure to grab the event device returns in a failure.
  *
  * @return TRUE if the device is a touchpad or FALSE otherwise.
  */
 static Bool
-event_query_is_touchpad(struct libevdev *evdev, BOOL test_grab)
+event_query_is_touchpad(struct libevdev *evdev)
 {
-    int ret = FALSE, rc;
-
-    if (test_grab) {
-        rc = libevdev_grab(evdev, LIBEVDEV_GRAB);
-        if (rc < 0)
-            return FALSE;
-    }
-
     /* Check for ABS_X, ABS_Y, ABS_PRESSURE and BTN_TOOL_FINGER */
     if (!libevdev_has_event_type(evdev, EV_SYN) ||
         !libevdev_has_event_type(evdev, EV_ABS) ||
         !libevdev_has_event_type(evdev, EV_KEY))
-        goto unwind;
+        return FALSE;
 
     if (!libevdev_has_event_code(evdev, EV_ABS, ABS_X) ||
         !libevdev_has_event_code(evdev, EV_ABS, ABS_Y))
-        goto unwind;
+        return FALSE;
 
     /* we expect touchpad either report raw pressure or touches */
     if (!libevdev_has_event_code(evdev, EV_KEY, BTN_TOUCH) &&
         !libevdev_has_event_code(evdev, EV_ABS, ABS_PRESSURE))
-        goto unwind;
+        return FALSE;
 
     /* all Synaptics-like touchpad report BTN_TOOL_FINGER */
     if (!libevdev_has_event_code(evdev, EV_KEY, BTN_TOOL_FINGER) ||
         libevdev_has_event_code(evdev, EV_ABS, BTN_TOOL_PEN)) /* Don't match wacom tablets */
-        goto unwind;
+        return FALSE;
 
-    ret = TRUE;
-
- unwind:
-    if (test_grab)
-        libevdev_grab(evdev, LIBEVDEV_UNGRAB);
-
-    return (ret == TRUE);
+    return TRUE;
 }
 
 #define PRODUCT_ANY 0x0000
@@ -565,8 +549,7 @@ EventQueryHardware(InputInfoPtr pInfo)
     SynapticsPrivate *priv = (SynapticsPrivate *) pInfo->private;
     struct eventcomm_proto_data *proto_data = priv->proto_data;
 
-    if (!event_query_is_touchpad(proto_data->evdev,
-                                 (proto_data) ? proto_data->need_grab : TRUE))
+    if (!event_query_is_touchpad(proto_data->evdev))
         return FALSE;
 
     xf86IDrvMsg(pInfo, X_PROBED, "touchpad found\n");
@@ -967,7 +950,7 @@ EventReadDevDimensions(InputInfoPtr pInfo)
         proto_data->axis_map[i] = -1;
     proto_data->cur_slot = -1;
 
-    if (event_query_is_touchpad(proto_data->evdev, proto_data->need_grab)) {
+    if (event_query_is_touchpad(proto_data->evdev)) {
         event_query_touch(pInfo);
         event_query_axis_ranges(pInfo);
     }
@@ -1001,7 +984,7 @@ EventAutoDevProbe(InputInfoPtr pInfo, const char *device)
 
             rc = libevdev_new_from_fd(fd, &evdev);
             if (rc >= 0) {
-                touchpad_found = event_query_is_touchpad(evdev, TRUE);
+                touchpad_found = event_query_is_touchpad(evdev);
                 libevdev_free(evdev);
             }
 
@@ -1043,7 +1026,7 @@ EventAutoDevProbe(InputInfoPtr pInfo, const char *device)
 
             rc = libevdev_new_from_fd(fd, &evdev);
             if (rc >= 0) {
-                touchpad_found = event_query_is_touchpad(evdev, TRUE);
+                touchpad_found = event_query_is_touchpad(evdev);
                 libevdev_free(evdev);
                 if (touchpad_found) {
                     xf86IDrvMsg(pInfo, X_PROBED, "auto-dev sets device to %s\n",
-- 
1.9.0