4.18-stable review patch. If anyone has any objections, please let me know.
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From: Nick Dyer nick.dyer@itdev.co.uk
[ Upstream commit 36f5d9ef26e52edff046b4b097855db89bf0cd4a ]
The driver only registers one input device, which uses the screen parameters from the first T9 instance. The first T63 instance also uses those parameters.
It is incorrect to send input reports from the second instances of these objects if they are enabled: the input scaling will be wrong and the positions will be mashed together.
This also causes problems on Android if the number of slots exceeds 32.
In the future, this could be handled by looking for enabled touch object instances and creating an input device for each one.
Signed-off-by: Nick Dyer nick.dyer@itdev.co.uk Acked-by: Benson Leung bleung@chromium.org Acked-by: Yufeng Shen miletus@chromium.org Signed-off-by: Dmitry Torokhov dmitry.torokhov@gmail.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/input/touchscreen/atmel_mxt_ts.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
--- a/drivers/input/touchscreen/atmel_mxt_ts.c +++ b/drivers/input/touchscreen/atmel_mxt_ts.c @@ -1658,10 +1658,11 @@ static int mxt_parse_object_table(struct break; case MXT_TOUCH_MULTI_T9: data->multitouch = MXT_TOUCH_MULTI_T9; + /* Only handle messages from first T9 instance */ data->T9_reportid_min = min_id; - data->T9_reportid_max = max_id; - data->num_touchids = object->num_report_ids - * mxt_obj_instances(object); + data->T9_reportid_max = min_id + + object->num_report_ids - 1; + data->num_touchids = object->num_report_ids; break; case MXT_SPT_MESSAGECOUNT_T44: data->T44_address = object->start_address;