Re: [PATCH v2] input: fix BTN_TOUCH reporting in input_mt_report_pointer_emulation
From: Benjamin Tissoires <hidden>
Date: 2014-10-28 20:47:59
Also in:
lkml
Hi Chung-yih, On Mon, Oct 27, 2014 at 6:08 AM, Chung-yih Wang [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From the definition of BTN_TOUCH, BTN_TOOL_<name> and BTN_TOUCH codes are orthogonal. BTN_TOUCH should be zero if there is no physical contact happened on device. With ABS_MT_DISTANCE information, the patch uses touch_count and finger_count to get the final reporting code for BTN_TOUCH and BTN_TOOL_<name>, respectively. Signed-off-by: Chung-yih Wang <redacted> --- drivers/input/input-mt.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c index fbe29fc..a2ab8e3 100644 --- a/drivers/input/input-mt.c +++ b/drivers/input/input-mt.c@@ -192,18 +192,21 @@ void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count) { struct input_mt *mt = dev->mt; struct input_mt_slot *oldest; - int oldid, count, i; + int oldid, i; + int touch_count, finger_count; if (!mt) return; oldest = NULL; oldid = mt->trkid; - count = 0; + touch_count = 0; + finger_count = 0; for (i = 0; i < mt->num_slots; ++i) { struct input_mt_slot *ps = &mt->slots[i]; int id = input_mt_get_value(ps, ABS_MT_TRACKING_ID); + int distance = input_mt_get_value(ps, ABS_MT_DISTANCE);
I don't really like this statement, even if it works. Some devices do not report ABS_MT_DISTANCE, and the value for them should not be considered as '0' but 'undefined'.
quoted hunk ↗ jump to hunk
if (id < 0) continue;@@ -211,12 +214,14 @@ void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count) oldest = ps; oldid = id; } - count++; + finger_count++; + if (distance == 0)
I'd rather test here if ABS_MT_DISTANCE is used, and then if the value is 0.
+ touch_count++;
}
- input_event(dev, EV_KEY, BTN_TOUCH, count > 0);
+ input_event(dev, EV_KEY, BTN_TOUCH, touch_count > 0);For the record, I *think* this will not break user space. This is used in the touchpad part of libinput, and does not seemed to be impacted by the change. Adding Peter and Hans in CC who can tell us if I am assuming right. Cheers, Benjamin
if (use_count)
- input_mt_report_finger_count(dev, count);
+ input_mt_report_finger_count(dev, finger_count);
if (oldest) {
int x = input_mt_get_value(oldest, ABS_MT_POSITION_X);
--
2.1.2