Feb 26, 2026

Fixing FocalTech Touchpad Freezing Issues on Linux (ASUS Vivobook S 16)

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This article documents the complete process of fixing intermittent freezing issues with FocalTech touchpads on ASUS Vivobook S 16 M5606WA, including problem analysis, multiple kernel patch attempts, and the final libinput quirks solution.

Problem Description

Device Information

Laptop: ASUS Vivobook S 16 M5606WA (AMD Ryzen AI, Strix Point)
Touchpad: FocalTech ASCF1201
- VID: 0x2808
- PID: 0x0231
- Bus: I2C-HID
System Environment: Gentoo Linux, KDE Plasma, Wayland
Kernel Version: 6.19.3-cachyos

Symptoms

The following issues occur when using the touchpad:

Intermittent cursor freezing: Cursor suddenly stops moving for 0.5-1 second during normal operation
Drag operation interruption: Suddenly releases during file/window dragging
Scrolling stutter: Noticeable pauses during two-finger scrolling
Worsening over time: Issues become more frequent with prolonged use

Similar problems were reported on Arch Linux BBS for Lenovo IdeaPad Slim 5 with FocalTech FTCS0038 touchpad (same VID 0x2808), suggesting this might be a common firmware issue with FocalTech touchpads.

Problem Analysis

Debugging Tools

Main tools used for debugging:

# View libinput events
sudo libinput debug-events

# View raw kernel events
sudo evtest /dev/input/eventX

# View device information
sudo libinput list-devices

Findings

Through libinput debug-events --verbose, we observed that during cursor freezing, libinput detected numerous palm event loops:

event5  - palm: touch 0 (TOUCH_UPDATE), palm detected (tool-palm)
event5  - gesture: [1fg] event GESTURE_STATE_UNKNOWN → GESTURE_EVENT_RESET → GESTURE_STATE_NONE
event5  - palm: touch 0 (TOUCH_END), palm detected (tool-palm)
event5  - button state: touch 0 from BUTTON_STATE_AREA    event BUTTON_EVENT_UP          to BUTTON_STATE_NONE
event5  - palm: touch 0 (TOUCH_BEGIN), palm detected (tool-palm)
event5  - button state: touch 0 from BUTTON_STATE_NONE    event BUTTON_EVENT_IN_AREA     to BUTTON_STATE_AREA
event5  - palm: touch 0 (TOUCH_END), palm detected (tool-palm)
event5  - button state: touch 0 from BUTTON_STATE_AREA    event BUTTON_EVENT_UP          to BUTTON_STATE_NONE
event5  - palm: touch 0 (TOUCH_BEGIN), palm detected (tool-palm)
...

Even during normal single-finger touch, libinput kept detecting palm detected (tool-palm), causing touch events to be discarded.

Further examination with evtest revealed the touchpad’s Confidence bit frequently toggled between 0 and 1 during normal operation. When Confidence=0, the kernel mapped it to MT_TOOL_PALM, causing libinput to discard the event.

Problem Chain Analysis

The complete issue chain was identified as:

FocalTech firmware's unstable Confidence bit (switches to 0 during normal touch)
    ↓
Kernel hid-multitouch sees Confidence=0
    ↓
Device matches MT_CLS_WIN_8 (with MT_QUIRK_CONFIDENCE)
    ↓
Kernel sets MT_TOOL_PALM (ABS_MT_TOOL_TYPE=2)
    ↓
libinput sees MT_TOOL_PALM → discards touch event
    ↓
Cursor freezing/jittering

Key Discoveries

Unreliable Confidence bit: FocalTech firmware incorrectly reports Confidence=0 during normal touch
No area sensor: Device doesn’t report ABS_MT_TOUCH_MAJOR, preventing libinput from using area-based palm detection

Solution 1: Kernel Patch (Disable Confidence Mapping)

Approach

Since the Confidence bit is unreliable, disable it at kernel level by creating a new device class MT_CLS_WIN_8_NO_CONFIDENCE with all Windows 8 precision touchpad quirks except MT_QUIRK_CONFIDENCE.

Implementation (kernel.patch)

// drivers/hid/hid-ids.h - Add device ID
#define I2C_VENDOR_ID_FOCALTECH        0x2808
#define I2C_PRODUCT_ID_FOCALTECH_ASCF1201    0x0231

// drivers/hid/hid-multitouch.c - Add device class definition
#define MT_CLS_WIN_8_NO_CONFIDENCE        0x0115

// Device class config - Note absence of MT_QUIRK_CONFIDENCE
{ .name = MT_CLS_WIN_8_NO_CONFIDENCE,
    .quirks = MT_QUIRK_ALWAYS_VALID |
        MT_QUIRK_IGNORE_DUPLICATES |
        MT_QUIRK_HOVERING |
        MT_QUIRK_CONTACT_CNT_ACCURATE |
        MT_QUIRK_STICKY_FINGERS |
        MT_QUIRK_WIN8_PTP_BUTTONS,
    .export_all_inputs = true },

// Device matching entry
{ .driver_data = MT_CLS_WIN_8_NO_CONFIDENCE,
    HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8,
        I2C_VENDOR_ID_FOCALTECH,
        I2C_PRODUCT_ID_FOCALTECH_ASCF1201) },

Full Patch

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index adad71cc8..9ac008210 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -500,6 +500,9 @@
 #define USB_DEVICE_ID_FFBEAST_RUDDER	0x5968
 #define USB_DEVICE_ID_FFBEAST_WHEEL	0x59d7
 
+#define I2C_VENDOR_ID_FOCALTECH		0x2808
+#define I2C_PRODUCT_ID_FOCALTECH_ASCF1201	0x0231
+
 #define USB_VENDOR_ID_FLATFROG		0x25b5
 #define USB_DEVICE_ID_MULTITOUCH_3200	0x0002
 
diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
index b1c3ef129..bd655fff1 100644
--- a/drivers/hid/hid-multitouch.c
+++ b/drivers/hid/hid-multitouch.c
@@ -231,6 +231,7 @@ static void mt_post_parse(struct mt_device *td, struct mt_application *app);
 #define MT_CLS_RAZER_BLADE_STEALTH		0x0112
 #define MT_CLS_SMART_TECH			0x0113
 #define MT_CLS_APPLE_TOUCHBAR			0x0114
+#define MT_CLS_WIN_8_NO_CONFIDENCE		0x0115
 #define MT_CLS_SIS				0x0457
 
 #define MT_DEFAULT_MAXCONTACT	10
@@ -428,6 +429,14 @@ static const struct mt_class mt_classes[] = {
 			MT_QUIRK_ALWAYS_VALID |
 			MT_QUIRK_CONTACT_CNT_ACCURATE,
 	},
+	{ .name = MT_CLS_WIN_8_NO_CONFIDENCE,
+		.quirks = MT_QUIRK_ALWAYS_VALID |
+			MT_QUIRK_IGNORE_DUPLICATES |
+			MT_QUIRK_HOVERING |
+			MT_QUIRK_CONTACT_CNT_ACCURATE |
+			MT_QUIRK_STICKY_FINGERS |
+			MT_QUIRK_WIN8_PTP_BUTTONS,
+		.export_all_inputs = true },
 	{ }
 };
 
@@ -2177,6 +2186,10 @@ static const struct hid_device_id mt_devices[] = {
 	{ .driver_data = MT_CLS_SERIAL,
 		MT_USB_DEVICE(USB_VENDOR_ID_CYGNAL,
 			USB_DEVICE_ID_FOCALTECH_FTXXXX_MULTITOUCH) },
+	{ .driver_data = MT_CLS_WIN_8_NO_CONFIDENCE,
+		HID_DEVICE(BUS_I2C, HID_GROUP_MULTITOUCH_WIN_8,
+			I2C_VENDOR_ID_FOCALTECH,
+			I2C_PRODUCT_ID_FOCALTECH_ASCF1201) },
 
 	/* GeneralTouch panel */
 	{ .driver_data = MT_CLS_GENERALTOUCH_TWOFINGERS,

Results

Successfully fixed freezing issues! The touchpad no longer freezes intermittently.

New issue: Complete loss of palm detection because:

Kernel no longer maps Confidence=0 to MT_TOOL_PALM
Device lacks area sensors, preventing libinput from area-based palm detection
Full palm contact moves the cursor instead of being ignored

While this solution fixes freezing, it sacrifices palm detection functionality, making it imperfect.

Solution 2: libinput Quirks (Recommended)

Approach

Instead of modifying the kernel, configure libinput to ignore incorrect palm detection by setting a high AttrPalmSizeThreshold. This filters out momentary palm misdetections while preserving actual palm detection.

Why This Solution is Better

Feature	Kernel Patch	libinput Quirks
Freezing	✅ Fixed	✅ Fixed
Palm Detection	❌ Lost	✅ Preserved
Maintenance	High (reapply on kernel updates)	Low (config file)
Complexity	High (kernel modification)	Low (single config file)

Technical Explanation

The key lies in the behavioral difference of Confidence bit:

Momentary misdetection: During normal touch, Confidence=0 appears briefly
Actual palm contact: During palm touch, Confidence=0 persists

By setting a high threshold, momentary misdetections are filtered while persistent palm contact still triggers detection.

Configuration File

Create /etc/libinput/local-overrides.quirks:

# FocalTech ASCF1201 Touchpad (ASUS Vivobook S 16 M5606WA)
#
# Hardware: FocalTech I2C-HID Precision Touchpad
# VID:PID:  0x2808:0x0231
#
# Issue: FocalTech firmware's unstable Confidence bit causes
# false MT_TOOL_PALM reports during normal touch, making libinput
# discard events and causing cursor freezing.
#
# Solution: Set high AttrPalmSizeThreshold to filter momentary
# palm misdetections while preserving actual palm detection.
#
# Reference: https://wayland.freedesktop.org/libinput/doc/latest/device-quirks.html

[FocalTech ASCF1201 Touchpad]
MatchUdevType=touchpad
MatchBus=i2c
MatchVendor=0x2808
MatchProduct=0x0231
AttrPalmSizeThreshold=1000

Applying Configuration

The configuration takes effect under these conditions:

System reboot (most reliable)
Log out and back in
Restart desktop session

Verify quirks activation with:

sudo libinput quirks list /dev/input/eventX

Where eventX is the touchpad device node (find with sudo libinput list-devices).

Conclusion

Root Cause

FocalTech touchpad firmware’s unstable Confidence bit implementation incorrectly reports Confidence=0 during normal touch, causing Linux kernel’s hid-multitouch driver to misidentify touches as palm contacts.

Solution Comparison

Solution	Approach	Result
Kernel Patch	Disable Confidence bit usage	⚠️ Works but loses palm detection
libinput Quirks	Filter incorrect palm detection	✅ Perfect solution

Applicability

This solution may work for other FocalTech touchpad devices such as:

Lenovo IdeaPad Slim 5 16AHP9 (FTCS0038, VID 0x2808)
Other laptops with FocalTech I2C-HID touchpads

For similar issues, try modifying the MatchProduct value in the configuration to match your device’s PID.

Fixing FocalTech Touchpad Freezing Issues on Linux (ASUS Vivobook S 16)

Problem Description

Device Information

Symptoms

Related Issues

Problem Analysis

Debugging Tools

Findings

Problem Chain Analysis

Key Discoveries

Solution 1: Kernel Patch (Disable Confidence Mapping)

Approach

Implementation (kernel.patch)

Full Patch

Results

Solution 2: libinput Quirks (Recommended)

Approach

Why This Solution is Better

Technical Explanation

Configuration File

Applying Configuration

Conclusion

Root Cause

Solution Comparison

Applicability

References