Input: hid-input - use a larger event buffer for MT devices

The MT devices produce a lot of data. Tell the underlying input device
approximately how many events will be sent per synchronization, to allow
for better buffering. The number is a template based on continuously
reporting details for each finger on a single hand.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/hid/hid-input.c

@@ -534,6 +534,9 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel
 			input_set_abs_params(input, usage->code, a, b, (b - a) >> 8, (b - a) >> 4);
 		else	input_set_abs_params(input, usage->code, a, b, 0, 0);
 
+		/* use a larger default input buffer for MT devices */
+		if (usage->code == ABS_MT_POSITION_X && input->hint_events_per_packet == 0)
+			input_set_events_per_packet(input, 60);
 	}
 
 	if (usage->type == EV_ABS &&