topic Re: HDMI display broken in i.MX Processors

HDMI display broken

oliverkuo — Wed, 13 Feb 2019 11:17:01 GMT

Hello,

We have a custom board with i.MX8MQ and 4GB DDR4 but set as 3GB since GPU driver issue described in Vivante GPU driver and 4GB DDR .

I have ported BSP android_O8.1.0_1.3.0_8M on our custom board, after download image to eMMC, I can boot into Android desktop.

However, if I run any APP for example FILE APP, the HDMI display will become blank, even I reboot the board, the Android boot animation can be showed properly, but HDMI display will become blank again after BOOT_COMPLETE message showed on console.

I can get back HDMI display by clearing userdata and fbmisc partitions but same phenomenon will be appeared again when I run APP.

I attached the first boot logs, running APP logs, 2nd boot logs and a short video after clear partitions.

I used non DRM build, my boot image and system image can run on i.MX8MQ_EVK with its uboot and open APP properly.

Can anyone help?

Re: HDMI display broken

oliverkuo — Thu, 14 Feb 2019 10:07:16 GMT

I've done more test about this issue.

I disabled PCI0/1 in fsl-imx8mq-evk.dts, because it will block kernel booting in our board, and built image by the setting "evk_8mq-userdebug".

Using all our board's images but replaced EVK's u-boot-imx8mq.imx on i.MX8MQ_EVK, HDMI worked well.

Using all EVK's images but replaced u-boot-imx8mq.imx on our board, same issue was appeared.

Since the major different in uboot is DDR init code in SPL, I attached related files.

The DDR4 train files were copied from ddr tool and used ddr_init.c/ddrphy_train.c generated by ddr tool.

Re: HDMI display broken

diegoadrian — Mon, 18 Feb 2019 21:19:27 GMT

Hello,

We recommend having the configuration as we have in our EVK board. Otherwise, we cannot guarantee if your board will work.

Furthermore, there are some recommendations that we have. However, we cannot guarantee if this could work.

You can try limiting the DDR size to 3GB with the "mem=3072MiB" kernel parameter.
You can try removing the GPU driver from the device tree to try 4GB memory size.

Hope this information can help you.

Best Regards,

Diego.

Re: HDMI display broken

oliverkuo — Tue, 19 Feb 2019 01:55:29 GMT

Hi Diego,

Thanks for your recommendations.

I revised the device tree file base on EVK board, the major different is the DDR4 not LPDDR4, so I can boot into Android on EVK by our boot image and system image; the configurations of our board and EVK are almost identical.

I've tried your recommendations, but they didn't help a lot.

The same phenomenon was still appeared after inserted "mem=3072MiB" to kernel boot parameter; unable to boot Android if GPU was disabled in device tree.

After getting back HDMI display by clearing userdata and fbmisc partitions, the HDMI became blank again when I swipe the Android lock screen.

I'll use another display interface and check if any different.

Thanks.

Re: HDMI display broken

oliverkuo — Wed, 03 Apr 2019 08:20:35 GMT

The new BSP Android_P900_100 can fix my issue.