Empty sync events clutter up logs and are a waste of CPU cycles. We can
avoid sending mt_sync events if touch is disabled or a specific slot is
unused. We can avoid sending full sync events if no events were generated.
Signed-off-by: Ping Cheng <ping.cheng@xxxxxxxxx>
Signed-off-by: Jason Gerecke <jason.gerecke@xxxxxxxxx>
---
drivers/hid/wacom_wac.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index ce9e8e9b48b6..3f992c9dca4d 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -2551,8 +2551,17 @@ static void wacom_wac_finger_slot(struct wacom_wac *wacom_wac,
int slot;
slot = input_mt_get_slot_by_key(input, hid_data->id);
- if (slot < 0)
+ if (slot < 0) {
return;
+ } else {
+ struct input_mt_slot *ps = &input->mt->slots[slot];
+ int mt_id = input_mt_get_value(ps, ABS_MT_TRACKING_ID);
+
+ if (!prox && mt_id < 0) {
+ // No data to send for this slot; short-circuit
+ return;
+ }
+ }
input_mt_slot(input, slot);
input_mt_report_slot_state(input, MT_TOOL_FINGER, prox);
@@ -2696,6 +2705,10 @@ static void wacom_wac_finger_report(struct hid_device *hdev,
struct input_dev *input = wacom_wac->touch_input;
unsigned touch_max = wacom_wac->features.touch_max;
+ /* if there was nothing to process, don't send an empty sync */
+ if (wacom_wac->hid_data.num_expected == 0)
+ return;
+
/* If more packets of data are expected, give us a chance to
* process them rather than immediately syncing a partial
* update.
--
2.32.0
