iMX6Q: HDMI can not support 1024x768

[jiejia]

Hi,

My MX6Q board is basically based on SABRELITE platform.

The HDMI port works well with "1920x1080@60HZ",

with the following kernel cmd line:

setenv hdmiargs  'video=mxcfb0:dev=hdmi,1920x1080@60,if=RGB24,bpp=32'

However, if I change the hdmiargs to 1024x768:

setenv hdmiargs  'video=mxcfb0:dev=hdmi,1024x768@60,if=RGB24,bpp=32'

The HDMI resolution is 640x480

I try to add 1024x768 to mxc_cea_mode[64] in mxc_edid.c, but I can't see anything in the screen. The terminal print these information every 3 or 4 seconds :

      Display is GTF capable

mxc_hdmi mxc_hdmi: same edid

How can I set the HDMI support 1024x768?

[igorpadykov]

Hi jie

1024x768 is not a CEA mode as discussed below

https://lists.yoctoproject.org/pipermail/meta-freescale/2014-November/011429.html

One can try attached patch and kernel command line as

"console=ttymxc0,115200 root=/dev/mmcblk1p1 rootwait rw no_console_suspend ip=none

video=mxcfb0:dev=ldb,LDB-XGA,if=RGB666,bpp=32

video=mxcfb1:dev=hdmi,1024x768m@60,if=RGB24,bpp=32 ldb=sep1".

Best regards

igor

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[jiejia]

Hi,igorpadykov

   Thanks for reply. I follow what you say, attached patch to kernel and change the kernel command line. However, it does not work.

The terminal print these information about every 2 seconds :

      Display is GTF capable

mxc_hdmi mxc_hdmi: same edid

[igorpadykov]

Hi jie

you can try other monitor, since 1024x768 is not a CEA mode

not all monitors will work

~igor

[jiejia]

Hi igor

I try to add 1024x768m@70 to the array of mxc_cea_mode[64] in mxc_edid.c, and it really work. However, when I try 1024x768m@60, it always print the two words. I sure my monitor support the 1024x768m@60.