> Date: Mon, 17 Aug 2026 14:50:42 +0000 (UTC) > From: Gabriel Tourillon <[email protected]>
Can you send me the acpidump output (the files from /var/db/acpi)? > Hello, > > I'm reporting an I2C touchpad problem on a Google Chromebook Edgar running > OpenBSD 7.9 amd64. > > Hardware: > > * Google Chromebook Edgar > * Intel Celeron N3160 > * 4 GB RAM > * Coreboot / MrChromebox 2606.1 > * OpenBSD 7.9 amd64 > > The touchpad is detected, but its interrupt cannot be established: > > dwiic1 at acpi0 I2C6 addr 0xfccdc000/0x1000 irq 37 > iic1 at dwiic1 > ietp0 at iic1 addr 0x15, can't establish interrupt > > The touchpad works with an Artix Linux live system on the same hardware, and > a USB mouse works normally under OpenBSD. > > I investigated the failure through ietp_attach(), iic_intr_establish(), and > dwiic_i2c_intr_establish(). The touchpad's ACPI interrupt resource refers to > the GPNC GPIO controller. > > I found that IETP attempts to establish its interrupt before the GPNC GPIO > driver has attached. At that point the ACPI node exists, but its GPIO > information has not been initialized. > > As an experiment, I modified dwiic to defer IETP discovery if its GPIO > provider has not attached yet. After the GPIO driver attaches, I rescan the > DWIIC ACPI devices. With this change the ordering becomes: > > chvgpio1 at acpi0 GPNC ... > ietp0 at iic1 addr 0x15 gpio 18 > > and the touchpad works. > > I have attached the experimental patch/workaround. This is intended mainly > to demonstrate the cause and provide a working test case. > > The modified source tree is available here in the branch chromebook-cb3-431 : > > > https://github.com/Grabyy/OpenBSD_src_Chromebook-CB3-431_custom/tree/chromebook-cb3-431 > > > If you need any additional information or testing, please let me know. I'm > new to OpenBSD kernel development, so I'm happy to provide anything that > would be useful. > > Thanks, > Gabriel. > > [2:application/octet-stream Show Save:dwiic-ietp.patch (2kB)] >
