Hi,
On 20-06-17 12:12, Bastien Nocera wrote:
----- 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
Right, having CONFIG_I2C_DESIGNWARE_PLATFORM=y will also fix the
backlight on many Bay Trail based devices, note that CONFIG_PWM_CRC
is already Y, it has been changed to a boolean in Kconfig for this
reason.
Regards,
Hans