On Sun, Jan 5, 2025 at 2:34 AM Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> wrote: > I would expect this works in Windows? Have you > checked if it uses 100 kHz or 400kHz there? The touchpad does work in Windows. I couldn't find a way to check the frequency there. I think that I need to do some more investigation into how I can find the "proper" frequency, though if anyone has any tips I would appreciate them greatly. In Windows, my touchpad does not have a vendor-provided driver, but uses the default I2C HID driver provided by Microsoft. Actually, my touchpad is registered as two devices: An "I2C HID Device" using the default "HIDI2C.inf" driver, and an "HID-compliant touch pad", using the default "input.inf" driver. Both were provided by Microsoft, so it appears there is no vendor-specific firmware here. I initially assumed that the driver would default to 100KHz (as being the lowest speed defined in drivers/i2c/busses/i2c-designware-common.c), but after reading Microsoft's documentation for I2C HID devices it appears that they recommend 400KHz or more [1]. After reading this, I tried forcing the speed to 1MHz in the kernel, which surprisingly also alleviated the laggy behavior. So it appears that the speed can be either 100KHz or 1MHz, but I think that in Windows it should be whatever the "default" defined by the Windows driver is. I tried finding the I2C frequency using the steps defined in the Microsoft guide to tracing I2C HID events using Logman [2], and this was (what I believe to be) the relevant snippet for setting up the I2C device, though it does not appear there is anything related to the controller frequency: [1]0004.0140::01/06/2025-02:34:21.359 [hidi2c][WDFDEVICE:0x000018796F20AFD8] Received WDFREQUEST 0x000018797575D918 (IOCTL_HID_READ_REPORT) on WDFQUEUE 0x000018796F20AC08 [1]0004.0140::01/06/2025-02:34:21.368 [hidi2c][WDFDEVICE:0x000018796F20AFD8] Error retrieving read WDFREQUEST 0x0000000000000000 from ReportQueue on interrupt status:0x8000001a(STATUS_NO_MORE_ENTRIES) [3]0004.3184::01/06/2025-02:34:21.369 [hidi2c][WDFDEVICE:0x000018796F20AFD8] D0Exit to target state D4 [0]0004.3184::01/06/2025-02:34:21.369 [hidi2c][WDFDEVICE:0x000018796F20AFD8] Power command (opcode:0x801) sent to device register 0x5 [0]0004.3184::01/06/2025-02:34:21.369 [hidi2c][WDFDEVICE:0x000018796F20AFD8] Successfully put device into sleep power state [0]0004.3184::01/06/2025-02:34:21.369 [hidi2c][WDFDEVICE:0x000018796F20AFD8] Deinitialized device HID state [0]0004.3184::01/06/2025-02:34:21.369 [hidi2c][WDFDEVICE:0x000018796F20AFD8] WdfObjectDelete closed and deleted SpbIoTarget [1]0004.0150::01/06/2025-02:34:23.172 [hidi2c]Created WDF driver object:0xFFFFE78696EE0E30 [3]0004.0150::01/06/2025-02:34:23.180 [hidi2c][WDFDEVICE:0x00001879716173C8] Created new device [1]0004.2364::01/06/2025-02:34:23.183 [hidi2c][WDFDEVICE:0x00001879716173C8] I2C resource found at index 0 with connection id: 0x1 [1]0004.2364::01/06/2025-02:34:23.183 [hidi2c][WDFDEVICE:0x00001879716173C8] Interrupt resource found at index 1 [1]0004.2364::01/06/2025-02:34:23.183 [hidi2c][WDFDEVICE:0x00001879716173C8] Created Spb IO Target and resources [1]0004.2364::01/06/2025-02:34:23.184 [hidi2c][WDFDEVICE:0x00001879716173C8] Found supported DSM function:1 [1]0004.2364::01/06/2025-02:34:23.184 [hidi2c][WDFDEVICE:0x00001879716173C8] HID Descriptor register address 0x1 retrieved from ACPI [1]0004.2364::01/06/2025-02:34:23.184 [hidi2c][WDFDEVICE:0x00001879716173C8] D0Entry from from previous state D4 [1]0004.2364::01/06/2025-02:34:23.185 [hidi2c][WDFDEVICE:0x00001879716173C8] HID descriptor retrieved from register 0x1 : LEN 30 VER 0x100 VID 0x4f3 PID 0x32b9 VER 0x4 RDL 679 RDA 0x2 IRA 0x3 IRML 31 ORA 0x4 ORML 0 CRA 0x5 DRA 0x6 [1]0004.2364::01/06/2025-02:34:23.185 [hidi2c][WDFDEVICE:0x00001879716173C8] Initialized device HID state [3]0004.2364::01/06/2025-02:34:23.185 [hidi2c][WDFDEVICE:0x00001879716173C8] Power command (opcode:0x800) sent to device register 0x5 [3]0004.2364::01/06/2025-02:34:23.185 [hidi2c][WDFDEVICE:0x00001879716173C8] Successfully put device into on power state [3]0004.2364::01/06/2025-02:34:23.185 [hidi2c][WDFDEVICE:0x00001879716173C8] WdfIoQueueRetrieveNextRequest failed to find idle notification request in IdleQueue WDFQUEUE 0x000018796F1CCFD8 status:0x8000001a(STATUS_NO_MORE_ENTRIES) [1]0004.2364::01/06/2025-02:34:23.186 [hidi2c][WDFDEVICE:0x00001879716173C8] Failed querying registry value for DoNotWaitForResetResponsestatus:0xc0000034(STATUS_OBJECT_NAME_NOT_FOUND) [1]0004.2364::01/06/2025-02:34:23.186 [hidi2c][WDFDEVICE:0x00001879716173C8] Starting timer for reset response - IO queue stopped [1]0004.2364::01/06/2025-02:34:23.186 [hidi2c][WDFDEVICE:0x00001879716173C8] Reset command sent to device register 0x5 [0]0004.0140::01/06/2025-02:34:23.188 [hidi2c][WDFDEVICE:0x00001879716173C8] Received WDFREQUEST 0x0000187962CC4C48 (IOCTL_HID_GET_DEVICE_DESCRIPTOR) on WDFQUEUE 0x000018796258EA28 [0]0004.0140::01/06/2025-02:34:23.188 [hidi2c][WDFDEVICE:0x00001879716173C8] Returning device descriptor to hidclass, report descriptor length 679 [0]0004.0140::01/06/2025-02:34:23.188 [hidi2c][WDFDEVICE:0x00001879716173C8] Completing WDFREQUEST 0x0000187962CC4C48 (IOCTL_HID_GET_DEVICE_DESCRIPTOR) with STATUS_SUCCESS [0]0004.0140::01/06/2025-02:34:23.188 [hidi2c][WDFDEVICE:0x00001879716173C8] Received reset response - starting IO queue [3]0004.0150::01/06/2025-02:34:23.189 [hidi2c][WDFDEVICE:0x00001879716173C8] Received WDFREQUEST 0x0000187962CC4C48 (IOCTL_HID_GET_DEVICE_ATTRIBUTES) on WDFQUEUE 0x000018796258EA28 [3]0004.0150::01/06/2025-02:34:23.189 [hidi2c][WDFDEVICE:0x00001879716173C8] Completing WDFREQUEST 0x0000187962CC4C48 (IOCTL_HID_GET_DEVICE_ATTRIBUTES) with STATUS_SUCCESS [3]0004.0150::01/06/2025-02:34:23.189 [hidi2c][WDFDEVICE:0x00001879716173C8] Received WDFREQUEST 0x0000187962CC4C48 (IOCTL_HID_GET_REPORT_DESCRIPTOR) on WDFQUEUE 0x000018796258EA28 [3]0004.0150::01/06/2025-02:34:23.209 [hidi2c][WDFDEVICE:0x00001879716173C8] Report descriptor of length 679 retrieved from register 0x2 [3]0004.0150::01/06/2025-02:34:23.209 [hidi2c][WDFDEVICE:0x00001879716173C8] Completing WDFREQUEST 0x0000187962CC4C48 (IOCTL_HID_GET_REPORT_DESCRIPTOR) with STATUS_SUCCESS [3]0004.0150::01/06/2025-02:34:23.209 [hidi2c][WDFDEVICE:0x00001879716173C8] Received WDFREQUEST 0x0000187962CC4C48 (IOCTL_HID_READ_REPORT) on WDFQUEUE 0x000018796258EA28 [3]0004.0150::01/06/2025-02:34:23.209 [hidi2c][WDFDEVICE:0x00001879716173C8] Received first ping pong read - enabling interrupt processing [3]0004.0150::01/06/2025-02:34:23.209 [hidi2c][WDFDEVICE:0x00001879716173C8] Received WDFREQUEST 0x0000187962CC48C8 (IOCTL_HID_READ_REPORT) on WDFQUEUE 0x000018796258EA28 [2]0790.0A3C::01/06/2025-02:34:23.225 [hidi2c][WDFDEVICE:0x00001879716173C8] Received WDFREQUEST 0x0000187962CC5A48 (IOCTL_HID_GET_STRING) on WDFQUEUE 0x000018796258EA28 [2]0790.0A3C::01/06/2025-02:34:23.225 [hidi2c][WDFDEVICE:0x00001879716173C8] Completing WDFREQUEST 0x0000187962CC5A48 (IOCTL_HID_GET_STRING) with STATUS_SUCCESS [2]0790.0A3C::01/06/2025-02:34:23.225 [hidi2c][WDFDEVICE:0x00001879716173C8] Received WDFREQUEST 0x0000187962CC5A48 (IOCTL_HID_GET_FEATURE) on WDFQUEUE 0x000018796258EA28 [0]0790.0A3C::01/06/2025-02:34:23.233 [hidi2c][WDFDEVICE:0x00001879716173C8] Completing WDFREQUEST 0x0000187962CC5A48 (IOCTL_HID_GET_FEATURE) with STATUS_SUCCESS [0]0790.0A3C::01/06/2025-02:34:23.234 [hidi2c][WDFDEVICE:0x00001879716173C8] Received WDFREQUEST 0x0000187962CC5A48 (IOCTL_HID_GET_FEATURE) on WDFQUEUE 0x000018796258EA28 [2]0790.0A3C::01/06/2025-02:34:23.242 [hidi2c][WDFDEVICE:0x00001879716173C8] Completing WDFREQUEST 0x0000187962CC5A48 (IOCTL_HID_GET_FEATURE) with STATUS_SUCCESS [2]0790.0A3C::01/06/2025-02:34:23.242 [hidi2c][WDFDEVICE:0x00001879716173C8] Received WDFREQUEST 0x0000187962CC5A48 (IOCTL_HID_DEVICERESET_NOTIFICATION) on WDFQUEUE 0x000018796258EA28 [2]0790.0A3C::01/06/2025-02:34:23.242 [hidi2c][WDFDEVICE:0x00001879716173C8] Pended device reset notification WDFREQUEST 0x0000187962CC5A48 to WDFQUEUE 0x0000187967F9EB08 [8]0004.020C::01/06/2025-02:34:23.243 [hidi2c][WDFDEVICE:0x00001879716173C8] Received WDFREQUEST 0x0000187962CC3208 (IOCTL_HID_SET_FEATURE) on WDFQUEUE 0x000018796258EA28 [0]0004.0300::01/06/2025-02:34:23.243 [hidi2c][WDFDEVICE:0x00001879716173C8] Received WDFREQUEST 0x0000187962CC1608 (IOCTL_HID_SET_FEATURE) on WDFQUEUE 0x000018796258EA28 [2]0004.020C::01/06/2025-02:34:23.244 [hidi2c][WDFDEVICE:0x00001879716173C8] Completing WDFREQUEST 0x0000187962CC3208 (IOCTL_HID_SET_FEATURE) with STATUS_SUCCESS [2]0004.0300::01/06/2025-02:34:23.244 [hidi2c][WDFDEVICE:0x00001879716173C8] Completing WDFREQUEST 0x0000187962CC1608 (IOCTL_HID_SET_FEATURE) with STATUS_SUCCESS [2]0790.0A3C::01/06/2025-02:34:23.247 [hidi2c][WDFDEVICE:0x00001879716173C8] Received WDFREQUEST 0x0000187962CC1608 (IOCTL_HID_SET_FEATURE) on WDFQUEUE 0x000018796258EA28 [8]0004.0300::01/06/2025-02:34:23.247 [hidi2c][WDFDEVICE:0x00001879716173C8] Received WDFREQUEST 0x0000187962CC3208 (IOCTL_HID_SET_FEATURE) on WDFQUEUE 0x000018796258EA28 [9]0004.020C::01/06/2025-02:34:23.247 [hidi2c][WDFDEVICE:0x00001879716173C8] Received WDFREQUEST 0x0000187962CC0F08 (IOCTL_HID_SET_FEATURE) on WDFQUEUE 0x000018796258EA28 [2]0790.0A3C::01/06/2025-02:34:23.247 [hidi2c][WDFDEVICE:0x00001879716173C8] Completing WDFREQUEST 0x0000187962CC1608 (IOCTL_HID_SET_FEATURE) with STATUS_SUCCESS [2]0004.0300::01/06/2025-02:34:23.248 [hidi2c][WDFDEVICE:0x00001879716173C8] Completing WDFREQUEST 0x0000187962CC3208 (IOCTL_HID_SET_FEATURE) with STATUS_SUCCESS [2]0004.020C::01/06/2025-02:34:23.248 [hidi2c][WDFDEVICE:0x00001879716173C8] Completing WDFREQUEST 0x0000187962CC0F08 (IOCTL_HID_SET_FEATURE) with STATUS_SUCCESS [3]0004.0140::01/06/2025-02:34:23.267 [hidi2c][WDFDEVICE:0x00001879716173C8] Received WDFREQUEST 0x0000187962CC0F08 (IOCTL_HID_READ_REPORT) on WDFQUEUE 0x000018796258EA28 [1]: https://learn.microsoft.com/en-us/windows-hardware/design/component-guidelines/touchpad-device-bus-connectivity#acpi-table-entries [2]: https://learn.microsoft.com/en-us/windows-hardware/drivers/hid/event-tracing#using-logmanexe
