Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

Input: elantech - don't set bit 1 of reg_10 when the no_hw_res quirk is set

The touchpad on the GIGABYTE U2442 not only stops communicating when we try
to set bit 3 (enable real hardware resolution) of reg_10, but on some BIOS
versions also when we set bit 1 (enable two finger mode auto correct).

I've asked the original reporter of:
https://bugzilla.kernel.org/show_bug.cgi?id=61151

To check that not setting bit 1 does not lead to any adverse effects on his
model / BIOS revision, and it does not, so this commit fixes the touchpad
not working on these versions by simply never setting bit 1 for laptop
models with the no_hw_res quirk.

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

authored by

Hans de Goede and committed by
Dmitry Torokhov
fb4f8f56 cd9e83e2

+3 -2
+3 -2
drivers/input/mouse/elantech.c
··· 849 849 if (etd->set_hw_resolution) 850 850 etd->reg_10 = 0x0b; 851 851 else 852 - etd->reg_10 = 0x03; 852 + etd->reg_10 = 0x01; 853 853 854 854 if (elantech_write_reg(psmouse, 0x10, etd->reg_10)) 855 855 rc = -1; ··· 1350 1350 } 1351 1351 1352 1352 /* 1353 - * Some hw_version 3 models go into error state when we try to set bit 3 of r10 1353 + * Some hw_version 3 models go into error state when we try to set 1354 + * bit 3 and/or bit 1 of r10. 1354 1355 */ 1355 1356 static const struct dmi_system_id no_hw_res_dmi_table[] = { 1356 1357 #if defined(CONFIG_DMI) && defined(CONFIG_X86)