Commit 36189cc3 authored by Hans de Goede's avatar Hans de Goede Committed by Dmitry Torokhov

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: default avatarPhilipp Wolfer <ph.wolfer@gmail.com>
Tested-by: default avatarPhilipp Wolfer <ph.wolfer@gmail.com>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent c1613497
......@@ -504,9 +504,12 @@ byte 5:
* reg_10
bit 7 6 5 4 3 2 1 0
0 0 0 0 0 0 0 A
0 0 0 0 R F T A
A: 1 = enable absolute tracking
T: 1 = enable two finger mode auto correct
F: 1 = disable ABS Position Filter
R: 1 = enable real hardware resolution
6.2 Native absolute mode 6 byte packet format
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
......
......@@ -11,6 +11,7 @@
*/
#include <linux/delay.h>
#include <linux/dmi.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/input.h>
......@@ -831,7 +832,11 @@ static int elantech_set_absolute_mode(struct psmouse *psmouse)
break;
case 3:
if (etd->set_hw_resolution)
etd->reg_10 = 0x0b;
else
etd->reg_10 = 0x03;
if (elantech_write_reg(psmouse, 0x10, etd->reg_10))
rc = -1;
......@@ -1330,6 +1335,22 @@ static int elantech_reconnect(struct psmouse *psmouse)
return 0;
}
/*
* Some hw_version 3 models go into error state when we try to set bit 3 of r10
*/
static const struct dmi_system_id no_hw_res_dmi_table[] = {
#if defined(CONFIG_DMI) && defined(CONFIG_X86)
{
/* Gigabyte U2442 */
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "GIGABYTE"),
DMI_MATCH(DMI_PRODUCT_NAME, "U2442"),
},
},
#endif
{ }
};
/*
* determine hardware version and set some properties according to it.
*/
......@@ -1390,6 +1411,9 @@ static int elantech_set_properties(struct elantech_data *etd)
*/
etd->crc_enabled = ((etd->fw_version & 0x4000) == 0x4000);
/* Enable real hardware resolution on hw_version 3 ? */
etd->set_hw_resolution = !dmi_check_system(no_hw_res_dmi_table);
return 0;
}
......
......@@ -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;
......
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