Package: linux-image-4.9.0-2-amd64
Version: 4.9.18-1
Touchpad and keyboard are not detected on Acer Chromebook 14 (and similar Braswell books) with kernel 4.9 when booting from a live stretch image. It successfully boots into Gnome session, but one needs to plug external mouse and keyboard to do anything. Same issue can be experienced on fedora after upgrading from kernel 4.8 (ok) to 4.9 (not ok) or 4.10.
For stretch and 4.9, there is nothing about keyboard in kern log, instead multiple failure messages are visible, like:
May 16 06:55:29 localhost kernel: [ 0.403004] cherryview-pinctrl INT33FF:01: Failed to translate GPIO to IRQ
May 16 06:55:29 localhost kernel: [ 0.448395] ERROR: Unable to locate IOAPIC for GSI 182
May 16 06:55:29 localhost kernel: [ 16.033266] genirq: Flags mismatch irq 182. 00002002 (ELAN0000:00) vs. 00000080 (i8042)
May 16 06:55:29 localhost kernel: [ 16.036059] elan_i2c i2c-ELAN0000:00: cannot register irq=182
May 16 06:55:29 localhost kernel: [ 16.051446] elan_i2c: probe of i2c-ELAN0000:00 failed with error -16
According to multiple sources, issue can be fixed by using CONFIG_PINCTRL_CHERRYVIEW=y
For related reports in other distros, please see:
https://bugs.archlinux.org/task/51281
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1630238
Thank you in advance.