From: Jeff Brown <jeffbrown@xxxxxxxxxx>
Calculate a default based on the number of ABS axes, REL axes,
and MT slots for the device during input device registration.
Signed-off-by: jeffbrown@xxxxxxxxxxx
---
drivers/input/input.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 46 insertions(+), 0 deletions(-)
diff --git a/drivers/input/input.c b/drivers/input/input.c
index d6e8bd8..c27292b 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -1746,6 +1746,49 @@ void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int
}
EXPORT_SYMBOL(input_set_capability);
+static inline bool is_mt_axis(int axis)
+{
+ return axis == ABS_MT_SLOT ||
+ (axis >= ABS_MT_FIRST && axis <= ABS_MT_LAST);
+}
+
+static void input_set_default_events_per_packet(struct input_dev *dev)
+{
+ int mt_slots;
+ int i;
+ int events;
+
+ if (dev->hint_events_per_packet)
+ return;
+
+ if (dev->mtsize)
+ mt_slots = dev->mtsize;
+ else if (test_bit(ABS_MT_TRACKING_ID, dev->absbit))
+ mt_slots = 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))
+ mt_slots = 2;
+ else
+ mt_slots = 0;
+
+ events = mt_slots + 1; /* count SYN_MT_REPORT and SYN_REPORT */
+
+ for (i = 0; i < ABS_CNT; i++) {
+ if (test_bit(i, dev->absbit)) {
+ if (is_mt_axis(i))
+ events += mt_slots;
+ else
+ events++;
+ }
+ }
+
+ for (i = 0; i < REL_CNT; i++)
+ if (test_bit(i, dev->relbit))
+ events++;
+
+ input_set_events_per_packet(dev, events);
+}
+
#define INPUT_CLEANSE_BITMASK(dev, type, bits) \
do { \
if (!test_bit(EV_##type, dev->evbit)) \
@@ -1784,6 +1827,9 @@ 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);
--
1.7.0.4
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