HID: multitouch: fix LG Melfas touchscreen
The LG Melfas touchscreen has a bad firmware where it declares the Contact ID
field as constant while it shouldn't. This messes up the autodetection and the
reporting of the events by hid-multitouch given that hid-input ignores constant
fields.
The autodetection is simply worked around by manually adding the device to
hid_have_special_driver[].
The processing of the events requires either a report fixup, or some specific
case handling. Given that the report fixup would require to basically rewrite
all the report descriptor, I went for the programatic way of fixing that after
the report descriptors are loaded.
Link: https://bugzilla.redhat.com/show_bug.cgi?id=1416181
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index ea36b55..1f6d0c0 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1933,6 +1933,7 @@ static const struct hid_device_id hid_have_special_driver[] = {
{ HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_LENOVO, USB_DEVICE_ID_LENOVO_CBTKBD) },
{ HID_USB_DEVICE(USB_VENDOR_ID_LENOVO, USB_DEVICE_ID_LENOVO_TPPRODOCK) },
#endif
+ { HID_USB_DEVICE(USB_VENDOR_ID_LG, USB_DEVICE_ID_LG_MELFAS_MT) },
{ HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_MX3000_RECEIVER) },
{ HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_S510_RECEIVER) },
{ HID_USB_DEVICE(USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_S510_RECEIVER_2) },