Linux 5.9/5.10 build config break brightness adjustment on Lenovo Miix2 8

[RussianNeuroMancer]

Hello!

I found that current build config for Linux 5.9 and 5.10 in mainline PPA break brightness adjustment on Linux Miix2 8 tablet. Brightness can not be adjusted and doesn't turn off during suspend.

Relevant build options:
CONFIG_I2C_DESIGNWARE_PLATFORM
CONFIG_INTEL_SOC_PMIC
CONFIG_GPIO_CRYSTAL_COVE
CONFIG_PWM_CRC
CONFIG_PMIC_OPREGION
CONFIG-BYTCRC_PMIC_OPREGION,

When all these build options is set to y I can no longer reproduce this issue.
I also think that enabling other related PMIC_OPREGION build options could help other BayTrail/CherryTrail-based devices as well:

CONFIG_CHTCRC_PMIC_OPREGION=y
CONFIG_XPOWER_PMIC_OPREGION=y
CONFIG_BXT_WC_PMIC_OPREGION=y
CONFIG_CHT_WC_PMIC_OPREGION=y
CONFIG_CHT_DC_TI_PMIC_OPREGION=y

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1907647

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.