ozone: evdev: Fix pen-related infinite recursion

If the pen device is disabled while the pen is near the screen it leads
to infinite recursion. This is because we make a call to disable palm
suppression, which revalidates device enablement. Post a task instead
of disabling inline to fix this.

The same thing happens if we lose events since Reinitialize() gained
a call to ReleaseButtons() when pen support was added, which calls
ReportEvents(), which can again call Reinitialize(). To fix that one,
kill ReleaseButtons() as ReleaseTouches() should be sufficient.

BUG=814071
TEST=powerd_dbus_suspend with pen touching screen

Change-Id: I8bb66feddc7961f1fa28d062133671ad1c46948c
Reviewed-on: https://chromium-review.googlesource.com/961386
Reviewed-by: Kevin Schoedel <kpschoedel@chromium.org>
Commit-Queue: Michael Spang <spang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543185}

ui/events/ozone/evdev/input_device_factory_evdev.cc

@@ -10,6 +10,7 @@
 
 #include <utility>
 
+#include "base/bind.h"
 #include "base/files/scoped_file.h"
 #include "base/memory/ptr_util.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ -509,6 +510,16 @@ void InputDeviceFactoryEvdev::EnablePalmSuppression(bool enabled) {
     return;
   palm_suppression_enabled_ = enabled;
 
+  // This function can be called while disabling pen devices, so don't disable
+  // inline here.
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::BindOnce(&InputDeviceFactoryEvdev::EnableDevices,
+                                weak_ptr_factory_.GetWeakPtr()));
+}
+
+void InputDeviceFactoryEvdev::EnableDevices() {
+  // TODO(spang): Fix the UI to not dismiss menus when we use
+  // ApplyInputDeviceSettings() instead of this function.
   for (const auto& it : converters_)
     it.second->SetEnabled(IsDeviceEnabled(it.second.get()));
 }

ui/events/ozone/evdev/input_device_factory_evdev.h

@@ -63,8 +63,6 @@ class EVENTS_OZONE_EVDEV_EXPORT InputDeviceFactoryEvdev {
 
   base::WeakPtr<InputDeviceFactoryEvdev> GetWeakPtr();
 
-  void EnablePalmSuppression(bool enabled);
-
  private:
   // Open device at path & starting processing events.
   void AttachInputDevice(std::unique_ptr<EventConverterEvdev> converter);
@@ -94,6 +92,8 @@ class EVENTS_OZONE_EVDEV_EXPORT InputDeviceFactoryEvdev {
   void SetBoolPropertyForOneType(const EventDeviceType type,
                                  const std::string& name,
                                  bool value);
+  void EnablePalmSuppression(bool enabled);
+  void EnableDevices();
 
   // Task runner for our thread.
   scoped_refptr<base::TaskRunner> task_runner_;

ui/events/ozone/evdev/touch_evdev_types.h

@@ -58,12 +58,7 @@ struct EVENTS_OZONE_EVDEV_EXPORT InProgressTouchEvdev {
   float tilt_y = 0;
   ui::EventPointerType reported_tool_type =
       ui::EventPointerType::POINTER_TYPE_TOUCH;
-
-  struct ButtonState {
-    bool down = false;
-    bool changed = false;
-  };
-  ButtonState btn_stylus;
+  bool stylus_button = false;
 };
 
 }  // namespace ui

ui/events/ozone/evdev/touch_event_converter_evdev.cc

@@ -228,6 +228,7 @@ void TouchEventConverterEvdev::Initialize(const EventDeviceInfo& info) {
                                                         MT_TOOL_FINGER);
       events_[i].tool_type = tool_type;
       events_[i].major = touch_major;
+      events_[i].stylus_button = false;
       if (events_[i].cancelled)
         cancelled_state = true;
     }
@@ -264,8 +265,6 @@ void TouchEventConverterEvdev::Initialize(const EventDeviceInfo& info) {
 }
 
 void TouchEventConverterEvdev::Reinitialize() {
-  ReleaseButtons();
-
   EventDeviceInfo info;
   if (!info.Initialize(fd_, path_)) {
     LOG(ERROR) << "Failed to synchronize state for touch device: "
@@ -297,7 +296,6 @@ void TouchEventConverterEvdev::OnEnabled() {
 
 void TouchEventConverterEvdev::OnDisabled() {
   ReleaseTouches();
-  ReleaseButtons();
   if (enable_palm_suppression_callback_) {
     enable_palm_suppression_callback_.Run(false);
   }
@@ -391,8 +389,7 @@ void TouchEventConverterEvdev::EmulateMultitouchEvent(
 void TouchEventConverterEvdev::ProcessKey(const input_event& input) {
   switch (input.code) {
     case BTN_STYLUS:
-      events_[current_slot_].btn_stylus.down = input.value;
-      events_[current_slot_].btn_stylus.changed = true;
+      events_[current_slot_].stylus_button = input.value;
       events_[current_slot_].altered = true;
       break;
     case BTN_TOOL_PEN:
@@ -520,7 +517,7 @@ void TouchEventConverterEvdev::ReportTouchEvent(
   ui::PointerDetails details(event.reported_tool_type, /* pointer_id*/ 0,
                              event.radius_x, event.radius_y, event.pressure,
                              /* twist */ 0, event.tilt_x, event.tilt_y);
-  int flags = event.btn_stylus.down ? ui::EventFlags::EF_LEFT_MOUSE_BUTTON : 0;
+  int flags = event.stylus_button ? ui::EventFlags::EF_LEFT_MOUSE_BUTTON : 0;
   dispatcher_->DispatchTouchEvent(TouchEventParams(
       input_device_.id, event.slot, event_type, gfx::PointF(event.x, event.y),
       details, timestamp, flags));
@@ -587,7 +584,6 @@ void TouchEventConverterEvdev::ReportEvents(base::TimeTicks timestamp) {
     event->was_touching = event->touching;
     event->was_delayed = event->delayed;
     event->altered = false;
-    event->btn_stylus.changed = false;
   }
 }
 
@@ -609,26 +605,14 @@ void TouchEventConverterEvdev::UpdateTrackingId(int slot, int tracking_id) {
 
 void TouchEventConverterEvdev::ReleaseTouches() {
   for (size_t slot = 0; slot < events_.size(); slot++) {
+    events_[slot].stylus_button = false;
     events_[slot].cancelled = true;
     events_[slot].altered = true;
   }
 
   ReportEvents(EventTimeForNow());
 }
 
-void TouchEventConverterEvdev::ReleaseButtons() {
-  for (size_t slot = 0; slot < events_.size(); slot++) {
-    InProgressTouchEvdev* event = &events_[slot];
-
-    if (event->btn_stylus.down) {
-      event->btn_stylus.down = false;
-      event->btn_stylus.changed = true;
-    }
-  }
-
-  ReportEvents(EventTimeForNow());
-}
-
 float TouchEventConverterEvdev::ScalePressure(int32_t value) {
   float pressure = value - pressure_min_;
   if (pressure_max_ - pressure_min_)

ui/events/ozone/evdev/touch_event_converter_evdev.h

@@ -90,7 +90,6 @@ class EVENTS_OZONE_EVDEV_EXPORT TouchEventConverterEvdev
 
   void UpdateTrackingId(int slot, int tracking_id);
   void ReleaseTouches();
-  void ReleaseButtons();
   void CancelAllTouches();
   bool IsPalm(const InProgressTouchEvdev& touch);
   // Normalize pressure value to [0, 1].