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authorJason Gerecke <killertofu@gmail.com>2021-07-19 22:55:32 +0200
committerJiri Kosina <jkosina@suse.cz>2021-07-28 11:45:40 +0200
commitccb51c2e3f0598934c3698f3645a3cb99add201c (patch)
treee9fbd7d1d29ed9d8a5ecb4f75c0a7e921a807858 /drivers/hid
parentHID: wacom: Short-circuit processing of touch when it is disabled (diff)
downloadlinux-ccb51c2e3f0598934c3698f3645a3cb99add201c.tar.xz
linux-ccb51c2e3f0598934c3698f3645a3cb99add201c.zip
HID: wacom: Avoid sending empty sync events
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@wacom.com> Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'drivers/hid')
-rw-r--r--drivers/hid/wacom_wac.c15
1 files changed, 14 insertions, 1 deletions
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.