From 7953794f741e94d30df9dafaaa4c031c85b891d6 Mon Sep 17 00:00:00 2001 From: Ping Cheng Date: Mon, 27 Oct 2025 13:37:42 -0700 Subject: HID: input: map HID_GD_Z to ABS_DISTANCE for stylus/pen HID_GD_Z is mapped to ABS_Z for stylus and pen in hid-input.c. But HID_GD_Z should be used to report ABS_DISTANCE for stylus and pen as described at: Documentation/input/event-codes.rst#n226 * ABS_DISTANCE: - Used to describe the distance of a tool from an interaction surface. This event should only be emitted while the tool is hovering, meaning in close proximity of the device and while the value of the BTN_TOUCH code is 0. If the input device may be used freely in three dimensions, consider ABS_Z instead. - BTN_TOOL_ should be set to 1 when the tool comes into detectable proximity and set to 0 when the tool leaves detectable proximity. BTN_TOOL_ signals the type of tool that is currently detected by the hardware and is otherwise independent of ABS_DISTANCE and/or BTN_TOUCH. This patch makes the correct mapping. The ABS_DISTANCE is currently not mapped by any HID usage in hid-generic driver. Signed-off-by: Ping Cheng Cc: stable@kernel.org Signed-off-by: Jiri Kosina --- drivers/hid/hid-input.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'drivers/hid/hid-input.c') diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index 2bbb645c2ff4..32a96ae2946f 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -878,7 +878,7 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel switch (usage->hid) { /* These usage IDs map directly to the usage codes. */ - case HID_GD_X: case HID_GD_Y: case HID_GD_Z: + case HID_GD_X: case HID_GD_Y: case HID_GD_RX: case HID_GD_RY: case HID_GD_RZ: if (field->flags & HID_MAIN_ITEM_RELATIVE) map_rel(usage->hid & 0xf); @@ -886,6 +886,22 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel map_abs_clear(usage->hid & 0xf); break; + case HID_GD_Z: + /* HID_GD_Z is mapped to ABS_DISTANCE for stylus/pen */ + if (field->flags & HID_MAIN_ITEM_RELATIVE) { + map_rel(usage->hid & 0xf); + } else { + if (field->application == HID_DG_PEN || + field->physical == HID_DG_PEN || + field->logical == HID_DG_STYLUS || + field->physical == HID_DG_STYLUS || + field->application == HID_DG_DIGITIZER) + map_abs_clear(ABS_DISTANCE); + else + map_abs_clear(usage->hid & 0xf); + } + break; + case HID_GD_WHEEL: if (field->flags & HID_MAIN_ITEM_RELATIVE) { set_bit(REL_WHEEL, input->relbit); -- cgit v1.2.3 From d6f4941f1b4f3e701e422dfbfee024264294f91f Mon Sep 17 00:00:00 2001 From: Benedek Kupper Date: Tue, 7 Oct 2025 22:35:44 +0200 Subject: drivers: hid: renegotiate resolution multipliers with device after reset 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 --- drivers/hid/hid-generic.c | 9 +++++++++ drivers/hid/hid-input.c | 7 +++++++ include/linux/hid.h | 1 + 3 files changed, 17 insertions(+) (limited to 'drivers/hid/hid-input.c') diff --git a/drivers/hid/hid-generic.c b/drivers/hid/hid-generic.c index 9e04c6d0fcc8..c2de916747de 100644 --- a/drivers/hid/hid-generic.c +++ b/drivers/hid/hid-generic.c @@ -70,6 +70,14 @@ static int hid_generic_probe(struct hid_device *hdev, return hid_hw_start(hdev, HID_CONNECT_DEFAULT); } +static int hid_generic_reset_resume(struct hid_device *hdev) +{ + if (hdev->claimed & HID_CLAIMED_INPUT) + hidinput_reset_resume(hdev); + + return 0; +} + static const struct hid_device_id hid_table[] = { { HID_DEVICE(HID_BUS_ANY, HID_GROUP_ANY, HID_ANY_ID, HID_ANY_ID) }, { } @@ -81,6 +89,7 @@ static struct hid_driver hid_generic = { .id_table = hid_table, .match = hid_generic_match, .probe = hid_generic_probe, + .reset_resume = hid_generic_reset_resume, }; module_hid_driver(hid_generic); diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index 2bbb645c2ff4..9f899ee83f0b 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -2400,6 +2400,13 @@ void hidinput_disconnect(struct hid_device *hid) } EXPORT_SYMBOL_GPL(hidinput_disconnect); +void hidinput_reset_resume(struct hid_device *hid) +{ + /* renegotiate host-device shared state after reset */ + hidinput_change_resolution_multipliers(hid); +} +EXPORT_SYMBOL_GPL(hidinput_reset_resume); + #ifdef CONFIG_HID_KUNIT_TEST #include "hid-input-test.c" #endif diff --git a/include/linux/hid.h b/include/linux/hid.h index a4ddb94e3ee5..dce862cafbbd 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -984,6 +984,7 @@ extern void hidinput_hid_event(struct hid_device *, struct hid_field *, struct h extern void hidinput_report_event(struct hid_device *hid, struct hid_report *report); extern int hidinput_connect(struct hid_device *hid, unsigned int force); extern void hidinput_disconnect(struct hid_device *); +void hidinput_reset_resume(struct hid_device *hid); struct hid_field *hid_find_field(struct hid_device *hdev, unsigned int report_type, unsigned int application, unsigned int usage); -- cgit v1.2.3