----- Original Message -----
On 06/16/2017 09:13 AM, Hans de Goede wrote:
> Hi All,
>
> For the last couple of months I've been working on improving Linux
> support for Intel Bay and Cherry Trail devices as a spare-time project.
>
> A lot of my changes for this have landed in the 4.12 kernel, see:
>
http://hansdegoede.livejournal.com/
>
> The proposed config changes enable various drivers to make these
> improvements available for Fedora users.
>
> Most of these changes just enable modules, but there is one change
> which also impacts non Bay and Cherry Trail x86_64 users, the proposed
> changes also change the I2C_DESIGNWARE controller options from module
> to built-in. This is necessary because Bay and Cherry Trail devices use
> an i2c attached PMIC which provides an ACPI OpRegion and this OpRegion
> must be available before any devices with _PS0 or _PS3 methods which
> use this OpRegion get their drivers bound to them.
>
> I'm not expecting any side-effects from this change, but I wanted
> to point this out just in case.
>
I thought there had previously been discussion about why we can't
have it built in but I have been unable to produce any evidence that
such a conversation ever existed. I might be confusing it with another
subsystem (GPIO?).
That's probably a discussion with me. I think it was for the Surface 3
battery support which needed:
CONFIG_I2C_DESIGNWARE_CORE=y
CONFIG_I2C_DESIGNWARE_PLATFORM=y
From:
https://bugzilla.kernel.org/show_bug.cgi?id=106231#c39
Benjamin would know more.
And possibly also:
+CONFIG_PWM_CRC=y
from commit fcb14e5f56b3d8daea308233b799d419cc02fd95 (and
d775331d9cc6659c6e91a6991c640e6abb049243) which is needed to get the
backlight working on the Surface 3 (and possibly other BayTrail/CherryTrail
devices)