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authorJeff Brown <jeffbrown@google.com>2011-04-18 10:08:02 -0700
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2011-04-18 10:15:43 -0700
commit80b4895aa4578e9372d76cd4063f82d0c3994d77 (patch)
tree0ac167a8b17e2550ff2d996d153ecbb59e05e643 /drivers/input/input.c
parentInput: evdev - indicate buffer overrun with SYN_DROPPED (diff)
downloadlinux-dev-80b4895aa4578e9372d76cd4063f82d0c3994d77.tar.xz
linux-dev-80b4895aa4578e9372d76cd4063f82d0c3994d77.zip
Input: estimate number of events per packet
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: Jeff Brown <jeffbrown@android.com> Reviewed-by: Henrik Rydberg <rydberg@euromail.se> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat (limited to 'drivers/input/input.c')
-rw-r--r--drivers/input/input.c40
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/input/input.c b/drivers/input/input.c
index d6e8bd8a851c..ebbceedc92f4 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -1746,6 +1746,42 @@ void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int
}
EXPORT_SYMBOL(input_set_capability);
+static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
+{
+ int mt_slots;
+ int i;
+ unsigned int events;
+
+ 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,
+ clamp(mt_slots, 2, 32);
+ } 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 (input_is_mt_axis(i))
+ events += mt_slots;
+ else
+ events++;
+ }
+ }
+
+ for (i = 0; i < REL_CNT; i++)
+ if (test_bit(i, dev->relbit))
+ events++;
+
+ return events;
+}
+
#define INPUT_CLEANSE_BITMASK(dev, type, bits) \
do { \
if (!test_bit(EV_##type, dev->evbit)) \
@@ -1793,6 +1829,10 @@ int input_register_device(struct input_dev *dev)
/* Make sure that bitmasks not mentioned in dev->evbit are clean. */
input_cleanse_bitmasks(dev);
+ if (!dev->hint_events_per_packet)
+ dev->hint_events_per_packet =
+ input_estimate_events_per_packet(dev);
+
/*
* If delay and period are pre-set by the driver, then autorepeating
* is handled by the driver itself and we don't do it in input.c.