From: Jeff Brown <jeffbrown@google.com>
Date: Thu, 17 Mar 2011 06:17:05 +0000 (-0700)
Subject: input: Set default events per packet for MT devices.
X-Git-Tag: firefly_0821_release~9834^2~41
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e5761351965ee8ef94f4fcdae923dd5aee52bf69;p=firefly-linux-kernel-4.4.55.git

input: Set default events per packet for MT devices.

Use the number of ABS_MT_SLOTs or ABS_MT_TRACKING_IDs to choose a
default number of events per packet.

Signed-off-by: jeffbrown@android.com
---

diff --git a/drivers/input/input.c b/drivers/input/input.c
index ab6982056518..5dc12e173ad3 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -1700,6 +1700,27 @@ void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int
 }
 EXPORT_SYMBOL(input_set_capability);
 
+static void input_set_default_events_per_packet(struct input_dev *dev)
+{
+	int slots;
+
+	if (dev->hint_events_per_packet)
+		return;
+
+	if (dev->mtsize)
+		slots = dev->mtsize;
+	else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit))
+		slots = min(20, dev->absinfo[ABS_MT_TRACKING_ID].maximum -
+			dev->absinfo[ABS_MT_TRACKING_ID].minimum + 1);
+	else if (test_bit(ABS_MT_POSITION_X, dev->absbit))
+		slots = 2;
+	else
+		slots = 0;
+
+	if (slots)
+		input_set_events_per_packet(dev, slots * 10);
+}
+
 #define INPUT_CLEANSE_BITMASK(dev, type, bits)				\
 	do {								\
 		if (!test_bit(EV_##type, dev->evbit))			\
@@ -1738,6 +1759,9 @@ int input_register_device(struct input_dev *dev)
 	const char *path;
 	int error;
 
+	/* Use a larger default input buffer for MT devices */
+	input_set_default_events_per_packet(dev);
+
 	/* Every input device generates EV_SYN/SYN_REPORT events. */
 	__set_bit(EV_SYN, dev->evbit);