HDMI not working in imx6AI board

[sanjayshekar]

Hello Everyone,

        My first post in this community...

We have IMX6 AI board on which we have loaded the prebuilt android images (4.3 JB) using MFG tool.

Currently we have trying to boot android with HDMI with the bootargs as mentioned in the "Android Quick Start Guide" document.

U-Boot > setenv bootcmd booti mmc3

U-Boot > setenv bootargs console=ttymxc0,115200 androidboot.console=ttymxc0 vmalloc=400M

init=/init video=mxcfb0:dev=hdmi,1920x1080M@60,bpp=32 video=mxcfb1:off video=mxcfb2:off

fbmem=28M androidboot.hardware=freescale

U-Boot > saveenv

We are able to see the console logs. But nothing comesup in UI. (We are using HDMI to DVI connector to connect to monitor.)

We have attached the boot logs for your reference.

Please help us to debug further.

Regards,

Sanjay.

Original Attachment has been moved to: boot_logs_imx6AI.zip

[emestee]

Hi,

There are two known issues in U-boot that are related to HDMI on iMX6 that were observed on SolidRun's Cubox-i platform (we build U-boot from a patched tree, so the issues may be specific to us). First, U-boot initializes clocks incorrectly which causes the video frequencies to be skewed down to ~53Hz instead of 60, which confuses many displays, especially Smart TVs. The kernel reinitializes the HDMI hardware correctly and thus there is no video problem. The other issue is that in some cases neither U-boot nor the kernel can initialize the hardware at all, in which case there is no video output entirely. There is some research going on, but as of now, there are no known solutions.

[sanjayshekar]

Hello Em Estee,

        Thank you for your reply. We could solve this issue by changing the DVI to HDMI cable to normal HDMI cable.

The display works properly if we use normal HDMI cable instead of DVI to HDMI convertor cable.

Regards,

Sanju.

[gmcclean]

You may have an EDID issue.

Monitors contain a small i2c ROM that the host platform powers and reads during boot. The ROM contains information such as supported video modes, native resolution, manufacturer and model number etc.

In my limited tests Android requires an EDID to function correctly.

[ramakrishnanven]

Hi Sanjay

         I am using HDMI to VGA Converter. I have connected a VGA Monitor. Will it work in this case