4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: KT Liao <kt.liao@xxxxxxxxxx>
[ Upstream commit d899520b0431e70279bfb5066ecb6dc91d0b7072 ]
One of Elan modules with sample version is 0x74 and hw_version is 0x03 has
a bug in absolute mode implementation, so let it run in default PS/2
relative mode.
Signed-off-by: KT Liao <kt.liao@xxxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/input/mouse/elantech.c | 11 +++++++++++
1 file changed, 11 insertions(+)
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -1711,6 +1711,17 @@ int elantech_init(struct psmouse *psmous
etd->samples[0], etd->samples[1], etd->samples[2]);
}
+ if (etd->samples[1] == 0x74 && etd->hw_version == 0x03) {
+ /*
+ * This module has a bug which makes absolute mode
+ * unusable, so let's abort so we'll be using standard
+ * PS/2 protocol.
+ */
+ psmouse_info(psmouse,
+ "absolute mode broken, forcing standard PS/2 protocol\n");
+ goto init_fail;
+ }
+
if (elantech_set_absolute_mode(psmouse)) {
psmouse_err(psmouse,
"failed to put touchpad into absolute mode.\n");