HDMI output 1024x768

Technical Support
, , ,
1

Hello,

i currently try to get my second display working via HDMI.
So i set up the following vidargs:
vidargs=video=mxcfb0:dev=hdmi,1024x768M@60,if=RGB24 video=mxcfb1:off video=mxcfb2:off video=mxcfb3:off fbmem=32M
When trying with three different screens i get the following outputs:

  • Screen 1: No Signal detected
  • Screen 2: Signal detected but black screen
  • Screen 3: Screen is displayed but with some horizontal blinking lines

The second problem I ran into was, as soon as I configured dual screen output (LVDS @1024x768 and HDMI @ 1024x768) :

vidargs=video=mxcfb0:dev=ldb,bpp=32 video=mxcfb1:dev=hdmi,1024x768M@60,if=RGB24 mxc_hdmi.only_cea=0 video=mxcfb2:off video=mxcfb3:off fbmem=32M

The LVDS screen looks like the timing changed ()and my boot log displays the following:

[    0.187854] mxc_sdc_fb fb.19: registered mxc display driver ldb
[    0.201557] mxc_sdc_fb fb.19: 1024x768 h_sync,r,l: 136,24,160  v_sync,l,u: 6,3,29 pixclock=65002000 Hz
[    0.213296] imx-ipuv3 2800000.ipu: IPU DMFC DP HIGH RESOLUTION: 1(0,1), 5B(2~5), 5F(6,7)
[    0.247235] mxc_sdc_fb fb.19: 1024x768 h_sync,r,l: 136,24,160  v_sync,l,u: 6,3,29 pixclock=65002000 Hz
[    0.277848] Console: switching to colour frame buffer device 128x48
[    0.321113] mxc_hdmi 20e0000.hdmi_video: Detected HDMI controller 0x13:0xa:0xa0:0xc1
[    0.321141] fbcvt: 1024x768@60: CVT Name - .786M3
[    0.321238] mxc_sdc_fb fb.20: registered mxc display driver hdmi
[    0.329820] mxc_sdc_fb fb.20: 1280x720 h_sync,r,l: 40,110,220  v_sync,l,u: 5,5,20 pixclock=74250000 Hz
[    0.346972] mxc_sdc_fb fb.21: mxcfb2 is turned off!
[    0.347042] mxc_sdc_fb fb.22: mxcfb3 is turned off!

For completion the corresponding device-tree config is this:

mxcfb1: fb@0 {
		compatible = "fsl,mxc_sdc_fb";
		disp_dev = "ldb";
		interface_pix_fmt = "RGB666";
		mode_str ="LDB-XGA";
		default_bpp = <32>;
		int_clk = <0>;
		late_init = <0>;
		status = "disabled";
	};

	mxcfb2: fb@1 {
		compatible = "fsl,mxc_sdc_fb";
		disp_dev = "hdmi";
		interface_pix_fmt = "RGB24";
		mode_str ="1024x768M@60";
		default_bpp = <16>;
		int_clk = <0>;
		late_init = <0>;
		status = "disabled";
	};

When running the HDMI at 1920x1080 everything is fine, except that my lvds-display displays certain gay tones blurry and flashy, content is okay tough.

Am i considering right, that a clone output for both Displays is not possible to configure directly?

Any idea would be greatly appreciated.

Thank you very much,

Moritz Wagner

2

So nobody managed to configure a mirrored dual screen output with the Apalis-iMX6 yet?
Do I really have to embed a hardware solution for this?

3

Have you tried that:

Activating/Deactivating Devices

An important device attribute is the status property. It allows devices to be activated/deactivated. A lot of devices are specified in the SoC level device trees, but are disabled by default. By referencing the base node (using the ampersand character and the label), the device can be enabled by any of the layers overwriting the status property.

For instance:

&mxcfb1 {
status = “okay”;
};

Device Tree Customization