Hi Dmitry,

Update /input/mouse/input-mt.c
Emit BTN_TOO_FINGER in input_mt_report_pointer_emulation if touchpad meets hover condition.

Thanks & BR	KT

-----Original Message-----
From: 'Dmitry Torokhov' [mailto:dmitry.torokhov@gmail.com] 
Sent: Friday, May 20, 2016 8:52 AM
To: 廖崇榮
Cc: linux-input@vger.kernel.org; linux-kernel@vger.kernel.org; zac.hsieh@emc.com.tw; '黃世鵬 經理'; 'Charles Mooney'; 'Agnes Cheng'; 'jeff'
Subject: Re: [PATCH] Input: Change BTN_TOOL_FINGER flag when hover event trigger

On Tue, May 17, 2016 at 10:20:40PM +0800, 廖崇榮 wrote:
> Hi Dmitry,
> 
> I want to confirm my thought for your idea to avoid misunderstanding.
> I think you want to encapsulate " BTN_TOOL_FINGER" in the [input_mt_report_pointer_emulation] if hover happen.
> Vendor driver only report "ABS_DISTANCE" and let [input_mt_report_pointer_emulation] emit BTN_TOOL_FINGER report without change function parameter.
> 
> Please let me know if my misunderstand about your idea.

Yes, that is correct. Something like this:

diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c index 54fce56..a1bbec9 100644
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -218,8 +218,23 @@ void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count)
 	}
 
 	input_event(dev, EV_KEY, BTN_TOUCH, count > 0);
-	if (use_count)
+
+	if (use_count) {
+		if (count == 0 &&
+		    !test_bit(ABS_MT_DISTANCE, dev->absbit) &&
+		    test_bit(ABS_DISTANCE, dev->absbit) &&
+		    input_abs_get_val(dev, ABS_DISTANCE) != 0) {
+			/*
+			 * Force reporting BTN_TOOL_FINGER for devices that
+			 * only report general hover (and not per-contact
+			 * distance) when contact is in proximity but not
+			 * on the surface.
+			 */
+			count = 1;
+		}
+
 		input_mt_report_finger_count(dev, count);
+	}
 
 	if (oldest) {
 		int x = input_mt_get_value(oldest, ABS_MT_POSITION_X);

--
Dmitry