[PATCH 1/3] hid-multitouch: ensure slots are initialized

From: Benjamin Tissoires
Date: Tue Jun 21 2011 - 09:02:09 EST


In case a device does not provide the feature "Maximum Contact Count",
or set it at 0, the maxcontacts field may be at 0 while calling
input_mt_init_slots.
This patch ensures that hid-multitouch will allways report
ABS_MT_SLOT and ABS_MT_TRACKING_ID to the user space.

This corrects a bug found with some Ilitek devices that has been
integrated in 3.0-rc0.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxx>
---
drivers/hid/hid-multitouch.c | 5 ++---
1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index 0b2dcd0..3867656 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -271,6 +271,8 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
}
return 1;
case HID_DG_CONTACTID:
+ if (!td->maxcontacts)
+ td->maxcontacts = MT_DEFAULT_MAXCONTACT;
input_mt_init_slots(hi->input, td->maxcontacts);
td->last_slot_field = usage->hid;
td->last_field_index = field->index;
@@ -547,9 +549,6 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
if (ret)
goto fail;

- if (!td->maxcontacts)
- td->maxcontacts = MT_DEFAULT_MAXCONTACT;
-
td->slots = kzalloc(td->maxcontacts * sizeof(struct mt_slot),
GFP_KERNEL);
if (!td->slots) {
--
1.7.4.4

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