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

Documentation/input/elantech.txt

+4 −1
Original line number Original line Diff line number Diff line
@@ -504,9 +504,12 @@ byte 5: 
* reg_10

* reg_10





   bit   7   6   5   4   3   2   1   0

   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

         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

6.2 Native absolute mode 6 byte packet format

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

drivers/input/mouse/elantech.c

+25 −1
Original line number Original line Diff line number Diff line
@@ -11,6 +11,7 @@ 
 */

 */





#include <linux/delay.h>

#include <linux/delay.h>

#include <linux/dmi.h>

#include <linux/slab.h>

#include <linux/slab.h>

#include <linux/module.h>

#include <linux/module.h>

#include <linux/input.h>

#include <linux/input.h>
@@ -831,7 +832,11 @@ static int elantech_set_absolute_mode(struct psmouse *psmouse) 
		break;

		break;





	case 3:

	case 3:

		if (etd->set_hw_resolution)

			etd->reg_10 = 0x0b;

			etd->reg_10 = 0x0b;

		else

			etd->reg_10 = 0x03;



		if (elantech_write_reg(psmouse, 0x10, etd->reg_10))

		if (elantech_write_reg(psmouse, 0x10, etd->reg_10))

			rc = -1;

			rc = -1;
@@ -1330,6 +1335,22 @@ static int elantech_reconnect(struct psmouse *psmouse) 
	return 0;

	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.

 * 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);

	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;

	return 0;

}

}

drivers/input/mouse/elantech.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -130,6 +130,7 @@ struct elantech_data { 
	bool jumpy_cursor;

	bool jumpy_cursor;

	bool reports_pressure;

	bool reports_pressure;

	bool crc_enabled;

	bool crc_enabled;

	bool set_hw_resolution;

	unsigned char hw_version;

	unsigned char hw_version;

	unsigned int fw_version;

	unsigned int fw_version;

	unsigned int single_finger_reports;

	unsigned int single_finger_reports;