kernel/linux.git/include/linux/hid.h, branch v6.19.11

drivers: hid: renegotiate resolution multipliers with device after reset

2025-11-26T16:21:48+00:00

The scroll resolution multipliers are set in the context of hidinput_connect(), which is only called at probe time: when the host changes the value on the device with a SET_REPORT(FEATURE), and the device accepts it, these multipliers are stored on the host side, and used to calculate the final scroll event values sent to userspace. After a USB suspend, the resume operation on many hubs and chipsets involve a USB reset signal as well. A reset on the device side clears all previous state information, including the value of the multiplier report. This reset is not handled by the multiplier handling logic, so what ends up happening is the host is still expecting high-resolution scroll events, but the device is reset to default resolution, making the effective, user-perceived scroll speed incredibly slow. The solution is to renegotiate the multiplier selection after each reset. This is not the only bug related to the high-resolution scrolling implementation in the kernel (the other one is https://bugzilla.kernel.org/show_bug.cgi?id=220144), but for this one, there is no device side workaround for, leading to poor user experience with our product: https://github.com/UltimateHackingKeyboard/firmware/issues/1155 https://github.com/UltimateHackingKeyboard/firmware/issues/1261 https://github.com/UltimateHackingKeyboard/firmware/pull/1355 This patch was tested by an affected user and has been reported to fix the issue (see discussion in 1355). Signed-off-by: Benedek Kupper Signed-off-by: Jiri Kosina

HID: core: Add printk_ratelimited variants to hid_warn() etc

2025-10-14T09:57:40+00:00

hid_warn_ratelimited() is needed. Add the others as part of the block. Signed-off-by: Vicki Pfau Signed-off-by: Jiri Kosina

Merge tag 'hid-for-linus-2025093001' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid

2025-10-04T22:38:04+00:00

Pull HID updates from Benjamin Tissoires: - haptic touchpad support (Angela Czubak and Jonathan Denose) - support for audio jack handling on DualSense Playstation controllers (Cristian Ciocaltea) - allow HID-BPF to rebind a driver to hid-multitouch (Benjamin Tissoires) - rework hidraw ioctls to make them safer (and tested) (Benjamin Tissoires) - various PIDFF and universal-PIDFF fixes/improvements (Tomasz Pakuła) - better configuration of Intel QuickI2C through ACPI (Xinpeng Sun) - other assorted cleanups and fixes * tag 'hid-for-linus-2025093001' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid: (58 commits) HID: playstation: Switch to scoped_guard() in {dualsense|dualshock4}_output_worker() HID: playstation: Silence sparse warnings for locking context imbalances HID: playstation: Update SP preamp gain comment line HID: intel-thc-hid: intel-quicki2c: support ACPI config for advanced features HID: core: Change hid_driver to use a const char* for name HID: hidraw: tighten ioctl command parsing selftests/hid: hidraw: forge wrong ioctls and tests them selftests/hid: hidraw: add more coverage for hidraw ioctls selftests/hid: update vmtest.sh for virtme-ng HID: playstation: Support DualSense audio jack event reporting HID: playstation: Support DualSense audio jack hotplug detection HID: playstation: Redefine DualSense input report status field HID: playstation: Prefer kzalloc(sizeof(*buf)...) HID: playstation: Document spinlock_t usage HID: playstation: Fix all alignment and line length issues HID: playstation: Correct spelling in comment sections HID: playstation: Replace uint{32,16,8}_t with u{32,16,8} HID: playstation: Simplify locking with guard() and scoped_guard() HID: playstation: Add spaces around arithmetic operators HID: playstation: Make use of bitfield macros ...

Merge branch 'for-6.18/haptic' into for-linus

2025-09-30T14:43:15+00:00

- Implement haptic touchpad support (Angela Czubak and Jonathan Denose)

HID: core: Change hid_driver to use a const char* for name

2025-09-17T09:48:01+00:00

name is never mutated by the core HID stack. Making name a const char* simplifies passing the string from Rust to C. Otherwise, it becomes difficult to pass a 'static lifetime CStr from Rust to a char*, rather than a const char*, due to lack of guarantee that the underlying data of the CStr will not be mutated by the C code. Signed-off-by: Rahul Rameshbabu Signed-off-by: Benjamin Tissoires

HID: add haptics page defines

2025-09-15T12:32:54+00:00

Introduce haptic usages as defined in HID Usage Tables specification. Add HID units for newton and gram. Signed-off-by: Angela Czubak Co-developed-by: Jonathan Denose Signed-off-by: Jonathan Denose Signed-off-by: Benjamin Tissoires

HID: i2c-hid: Make elan touch controllers power on after panel is enabled

2025-08-25T16:18:39+00:00

Introduce a new HID quirk to indicate that this device has to be enabled after the panel's backlight is enabled, and update the driver data for the elan devices to enable this quirk. This cannot be a I2C HID quirk because the kernel needs to acknowledge this before powering up the device and read the VID/PID. When this quirk is enabled, register .panel_enabled()/.panel_disabling() instead for the panel follower. Also rename the *panel_prepare* functions into *panel_follower* because they could be called in other situations now. Fixes: bd3cba00dcc63 ("HID: i2c-hid: elan: Add support for Elan eKTH6915 i2c-hid touchscreens") Fixes: d06651bebf99e ("HID: i2c-hid: elan: Add elan-ekth6a12nay timing") Reviewed-by: Douglas Anderson Signed-off-by: Pin-yen Lin Acked-by: Jiri Kosina Signed-off-by: Douglas Anderson Link: https://lore.kernel.org/r/20250818115015.2909525-2-treapking@chromium.org

HID: core: Improve the kerneldoc for hid_report_len()

2025-07-15T15:28:27+00:00

The kerneldoc for hid_report_len() needs to be improved. The description of the @report argument is ungrammatical, and the documentation does not explain under what circumstances the report length will include the byte reserved for the report ID. Let's fix up the kerneldoc. Signed-off-by: Alan Stern Link: https://patch.msgid.link/1c8416cb-7347-4a06-b00a-20518069d263@rowland.harvard.edu Signed-off-by: Benjamin Tissoires

HID: rate-limit hid_warn to prevent log flooding

2025-06-20T13:34:36+00:00

Syzkaller can create many uhid devices that trigger repeated warnings like: "hid-generic xxxx: unknown main item tag 0x0" These messages can flood the system log, especially if a crash occurs (e.g., with a slow UART console, leading to soft lockups). To mitigate this, convert `hid_warn()` to use `dev_warn_ratelimited()`. This helps reduce log noise and improves system stability under fuzzing or faulty device scenarios. Signed-off-by: Li Chen Signed-off-by: Jiri Kosina

HID: core: Add functions for HID drivers to react on first open and last close call

2025-05-13T13:59:03+00:00

Adds a new function to the hid_driver struct that is called when the userspace starts using the device, and another one that is called when userspace stop using the device. With this a hid driver can implement special suspend handling for devices currently not in use. Signed-off-by: Werner Sembach Link: https://patch.msgid.link/20250211133950.422232-1-wse@tuxedocomputers.com Signed-off-by: Benjamin Tissoires