Backlight brightness slider malfunctions after Android 13 updated

[KyleChang]

On Android 11, the backlight brightness slider works.

On Android 13, Settings->Display->Brightness level can't work.

But we can use the following command to control brightness in kernel space:

echo 150 > sys/class/backlight/pwm-backlight/brightness

The development environment shows below:

1. NXP reference design code base:

i.MX8MQ platform / Android 13.0.0_2.0.0 (L6.1.22_2.0.0 BSP)

2. Device Tree

pwm3_bl: pwm-backlight {

    compatible = "pwm-backlight";

    pwms = <&pwm3 0 1000000 0>;

    ......

}

&pwm3 {

    pinctrl-names = "default";

    pinctrl-0 = <&pinctrl_pwm3>;

    status = "okay";

};

&iomuxc {

  pinctrl_pwm3: pwm3grp {

    fsl,pins = < MX8MQ_IOMUXC_SPDIF_TX_PWM3_OUT

3. Driver and ko 

drivers/video/backlight/pwm_bl.c (pwm_bl.ko declared in SharedBoardConfig.mk)

Does NXP have any patch or porting guide for Android 13 AOSP/BSP to fix the issue?

BTW, please take a look at the link below, Google Pixel 4a seems to have the same issue.

https://www.reddit.com/r/Pixel4a/comments/wqnpn4/brightness_slider_acts_weirdly_after_android_13/

[jimmychan]

I check the code (nxp side). Seems there is no problem compare with the source code of Android 11.

https://github.com/nxp-imx-android/android-imx_platform_hardware_imx/blob/android-13.0.0_2.2.0/displ...

[KyleChang]

Do you mean the brightness slider function of i.MX 8M Quad EVK board can work well on Android 13 ?

[jimmychan]

I think it is AOSP issue. you may check this issue in the developer forum of Android.

[KyleChang]

We download & build Android image based on NXP user guide,
So the Reference Design of i.MX 8MQ should work well for basic function.

Do you mean the Reference Design of i.MX 8MQ have the same issue?

[KyleChang]

Dear Jimmy,

NXP reference design works for backlight control, it works.
Please close the issue, thanks.

[jimmychan · Accepted solution]

Thanks for your feedback.

I don't have i.MX8MQ board. I have i.MX8MP EVK + mipi panel. I also tried the brightness slider on it. i.MX8MP also work.