i.mx6 Yocto HDMI resolution

[erikraynolds]

Dears,

I run i.MX6QP Sabre - Auto AI with Yocto 3.14.52 with X11. I have monitor Siemens Fujitsu P20-2 (Fujitsu SCENICVIEW P20-2 Specs - CNET ) with 1600x1200@60Hz default resolution. I am not able to get HDMI output there.

I do setting at boot:

setenv mmcargs 'setenv bootargs console=ttymxc0,115200 root=/dev/mmcblk2p2 rootwait rw video=mxcfb0:dev=hdmi,1600x1200M@60,if=RGB24'

I tried different resolution such as 1400x1050, 1280x960, 1152x864, 1024x768, 800x600 and none is working.

My Yocto/Linux is working fine since I can run at different monitor.

Any idea how to get HDMI output?

Regards,

Erik

[igorpadykov]

Hi Erik

i.MX6Q/QP HDMI supports modes defined in Table 33-3. Video Modes

i.MX6DQ Reference Manual

http://cache.freescale.com/files/32bit/doc/ref_manual/IMX6DQRM.pdf

In linux HDMI supports only modes which are found in

drivers/video/mxc/mxc_edid.c const struct fb_videomode and

one can add new resolution into "drivers/video/mxc/mxc_edid.c",

structure mxc_cea_mode[].

  Note: all those HDMI formats are defined in CEA-861-D specification,

CEA-861-D specification defined format 1 to 59, one can add format [N]

for another new resolutions.

One can run the followed command to double check if the mode had been added successfully or not.

# cat  /sys/class/graphics/fb0/modes

If the HDMI display can't support these formats from its EDID,  the format can't been seen.

Also one can also use PC tool "EDIDViewer" to check the HDMI

display if it can support the necessary resolutions or not.

EDIDViewer:

http://www.softpedia.com/get/System/System-Info/EDID-Viewer.shtml

Best regards

igor

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