topic Re: HDMI not working in imx6AI board in i.MX Processors

HDMI not working in imx6AI board

sanjayshekar — Tue, 28 Jan 2014 15:39:57 GMT

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

Re: HDMI not working in imx6AI board

emestee — Mon, 03 Feb 2014 13:02:22 GMT

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.

Re: HDMI not working in imx6AI board

sanjayshekar — Tue, 18 Mar 2014 07:14:33 GMT

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.

Re: HDMI not working in imx6AI board

ramakrishnanven — Mon, 07 Apr 2014 12:20:16 GMT

Hi Sanjay

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

Re: HDMI not working in imx6AI board

gmcclean — Mon, 07 Apr 2014 12:42:20 GMT

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.