Input: elantech - fix touchpad initialization on Gigabyte U2442

The hw_version 3 Elantech touchpad on the Gigabyte U2442 does not accept
0x0b as initialization value for r10, this stand-alone version of the
driver: http://planet76.com/drivers/elantech/psmouse-elantech-v6.tar.bz2

Uses 0x03 which does work, so this means not setting bit 3 of r10 which
sets: "Enable Real H/W Resolution In Absolute mode"

Which will result in half the x and y resolution we get with that bit set,
so simply not setting it everywhere is not a solution. We've been unable to
find a way to identify touchpads where setting the bit will fail, so this
patch uses a dmi based blacklist for this.

https://bugzilla.kernel.org/show_bug.cgi?id=61151

Cc: stable@vger.kernel.org
Reported-by: Philipp Wolfer <ph.wolfer@gmail.com>
Tested-by: Philipp Wolfer <ph.wolfer@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/input/mouse/elantech.h b/drivers/input/mouse/elantech.h
index 036a04abaef7..9e0e2a1f340d 100644
--- a/drivers/input/mouse/elantech.h
+++ b/drivers/input/mouse/elantech.h
@@ -130,6 +130,7 @@ struct elantech_data {
 	bool jumpy_cursor;
 	bool reports_pressure;
 	bool crc_enabled;
+	bool set_hw_resolution;
 	unsigned char hw_version;
 	unsigned int fw_version;
 	unsigned int single_finger_reports;