This is a note to let you know that I've just added the patch titled

Input: i8042 - enable MUX on Sony VAIO VGN-CS series to fix touchpad

to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: input-i8042-enable-mux-on-sony-vaio-vgn-cs-series-to-fix-touchpad.patch and it can be found in the queue-3.18 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 04bb1719c4de94700056241d4c0fe3c1413f5aff Mon Sep 17 00:00:00 2001

From: Ondrej Zary linux@rainbow-software.org Date: Tue, 3 Apr 2018 10:24:34 -0700 Subject: Input: i8042 - enable MUX on Sony VAIO VGN-CS series to fix touchpad

From: Ondrej Zary linux@rainbow-software.org

commit 04bb1719c4de94700056241d4c0fe3c1413f5aff upstream.

The touch sensor buttons on Sony VAIO VGN-CS series laptops (e.g. VGN-CS31S) are a separate PS/2 device. As the MUX is disabled for all VAIO machines by the nomux blacklist, the data from touch sensor buttons and touchpad are combined. The protocol used by the buttons is probably similar to the touchpad protocol (both are Synaptics) so both devices get enabled. The controller combines the data, creating a mess which results in random button clicks, touchpad stopping working and lost sync error messages: psmouse serio1: TouchPad at isa0060/serio1/input0 lost sync at byte 4 psmouse serio1: TouchPad at isa0060/serio1/input0 lost sync at byte 1 psmouse serio1: TouchPad at isa0060/serio1/input0 lost sync at byte 1 psmouse serio1: TouchPad at isa0060/serio1/input0 lost sync at byte 1 psmouse serio1: TouchPad at isa0060/serio1/input0 lost sync at byte 1 psmouse serio1: issuing reconnect request

Add a new i8042_dmi_forcemux_table whitelist with VGN-CS. With MUX enabled, touch sensor buttons are detected as separate device (and left disabled as there's currently no driver), fixing all touchpad problems.

Signed-off-by: Ondrej Zary linux@rainbow-software.org Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov dmitry.torokhov@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/input/serio/i8042-x86ia64io.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)

--- a/drivers/input/serio/i8042-x86ia64io.h +++ b/drivers/input/serio/i8042-x86ia64io.h @@ -712,6 +712,20 @@ static const struct dmi_system_id __init { } };

+static const struct dmi_system_id i8042_dmi_forcemux_table[] __initconst = { + { + /* + * Sony Vaio VGN-CS series require MUX or the touch sensor + * buttons will disturb touchpad operation + */ + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"), + DMI_MATCH(DMI_PRODUCT_NAME, "VGN-CS"), + }, + }, + { } +}; + /* * Some Wistron based laptops need us to explicitly enable the 'Dritek * keyboard extension' to make their extra keys start generating scancodes. @@ -1124,6 +1138,9 @@ static int __init i8042_platform_init(vo if (dmi_check_system(i8042_dmi_nomux_table)) i8042_nomux = true;

+ if (dmi_check_system(i8042_dmi_forcemux_table)) + i8042_nomux = false; + if (dmi_check_system(i8042_dmi_notimeout_table)) i8042_notimeout = true;

Patches currently in stable-queue which might be from linux@rainbow-software.org are

queue-3.18/input-i8042-enable-mux-on-sony-vaio-vgn-cs-series-to-fix-touchpad.patch