Input: MT - initialize slots to unused
For MT slots, the ABS_MT_TRACKING_ID determines whether a slot is in use,
but currently leaves initialization up to the drivers. This patch sets the
slot state to unused upon creation.
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/input.c b/drivers/input/input.c
index a9b025f..ab69820 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -1599,11 +1599,14 @@
* @dev: input device supporting MT events and finger tracking
* @num_slots: number of slots used by the device
*
- * This function allocates all necessary memory for MT slot handling
- * in the input device, and adds ABS_MT_SLOT to the device capabilities.
+ * This function allocates all necessary memory for MT slot handling in the
+ * input device, and adds ABS_MT_SLOT to the device capabilities. All slots
+ * are initially marked as unused iby setting ABS_MT_TRACKING_ID to -1.
*/
int input_mt_create_slots(struct input_dev *dev, unsigned int num_slots)
{
+ int i;
+
if (!num_slots)
return 0;
@@ -1614,6 +1617,10 @@
dev->mtsize = num_slots;
input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0);
+ /* Mark slots as 'unused' */
+ for (i = 0; i < num_slots; i++)
+ dev->mt[i].abs[ABS_MT_TRACKING_ID - ABS_MT_FIRST] = -1;
+
return 0;
}
EXPORT_SYMBOL(input_mt_create_slots);