iMX6Q Android 8.0 1366x768 support

[mosesyang]

Hi, we are having problem using a 1366x768 LVDS panel with Android 8.0.

When the system boots into kernel, we can see the 4 penguins get displayed correctly, and if we direct the console message to the LVDS, it also displays correctly.

However, once Android kicks in, the images start to tear off, even during boot animation.

We have a imx6q version and a imx6s verison. Both exhibit the same symptom.

The same LVDS timing definition in device tree was used in L5.0.2, and it worked fine.

We then compiled a zImage and a dtb file using the exactly same kernel source from Android 8.0(o8.0.0_4.9.17), put it into a Yocto 4.9.11 image, and the display worked just fine, so it doesn't seem to be kernel related.

Please see the attached images for the teared Android screenshot and the good Yocto screenshot.

It looks like the issue is specific to Android 8.0 system and 1366x768 resolution.

We tried a 1024X600 panel and 1280x800 panel without this issue.

Could anyone provide any insight of how to fix this issue?

Thank you.

[diegoadrian]

Hello,

The screen resolution could be due to several problems. Probably our Android 8 BSP does not support the frequency of your screen. Nevertheless, this should be a Problem with the Android framework, since the tux logos are showing correctly, giving that the kernel is uploading on the correct way your screen. 

Is there a way that you can test with our latest Android 9 BSP?

Best regards,

Diego.

[mosesyang]

Hi Diego,

Thanks for the reply.

We actually figured out a way to fix this.

The Android 8 framework does not seem to like 1366x768, but after we change it to 1360x768, the issue was gone.

Although we lost a few pixels, the output is good enough.

Hopefully this is helpful for other people.

Moses

[chpub70]

1360x768, both x and y pixel must be divisible by 4. Otherwise will have issue.