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Input: psmouse - ensure that focaltech reports consistent coordinates

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We don't know whether x_max or y_max really hold the maximum possible
coordinates, and we don't know for sure whether we correctly interpret the
coordinates sent by the touchpad, so we clamp the reported values to
prevent confusion in userspace code.

Signed-off-by: Mathias Gottschlag <mgottschlag@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Mathias Gottschlag 2015-03-07 13:27:08 -08:00 committed by Dmitry Torokhov
parent 3e98452519
commit 679d83ea93
1 changed files with 10 additions and 2 deletions
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12
drivers/input/mouse/focaltech.c
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@ -126,9 +126,17 @@ static void focaltech_report_state(struct psmouse *psmouse)
input_mt_slot(dev, i);
input_mt_report_slot_state(dev, MT_TOOL_FINGER, active);
if (active) {
input_report_abs(dev, ABS_MT_POSITION_X, finger->x);
unsigned int clamped_x, clamped_y;
/*
* The touchpad might report invalid data, so we clamp
* the resulting values so that we do not confuse
* userspace.
*/
clamped_x = clamp(finger->x, 0U, priv->x_max);
clamped_y = clamp(finger->y, 0U, priv->y_max);
input_report_abs(dev, ABS_MT_POSITION_X, clamped_x);
input_report_abs(dev, ABS_MT_POSITION_Y,
priv->y_max - finger->y);
priv->y_max - clamped_y);
}
}
input_mt_report_pointer_emulation(dev, true);