Using HDMI as mirror of primary lvds display

[kaushalbisht2005]

Our device is based on i.MX6 Dual and we are using 2 displays:

1. LVDS (800x480@60) (primary)

2. HDMI (1920x1080@60)

As we already know, iMX 6Dual supports the two display but the question is how to make the HDMI display gives the mirror image of the primary display. 

video=mxcfb0:dev=hdmi,1920x1080M@60,if=RGB24

video=mxcfb1:dev=ldb,800x48M@60,if=RGB24

OR

video=mxcfb1:dev=hdmi,1920x1080M@60,if=RGB24

video=mxcfb0:dev=ldb,800x48M@60,if=RGB24

We have tried above parameter but the issue is same. only single display works, which is assigned to mxcfb0.

Also, When you run below commands, you can see the random data on the secondary display. (shows as time two display can work)

$ echo 0 > /sys/class/graphics/fb2/blank

$ cat /dev/urandom > /dev/fb2

Please confirm is there any code we need to add/integrate to get the mirror of primary display automatically. 

[kaushalbisht2005 · Accepted solution]

We are able to make an HDMI display as Extended and Mirror for the below distro and image.

Distro = fsl-imx-wayland 

Image = core-image-weston

Kernel = cgtimx6__zeus-5.4.3-1.0.0

In our case 

Primary display = LVDS (ldb,800x480M@60)

Secondary display = HDMI (hdmi,1920x1080M@60)

U-boot changes

video=mxcfb0:dev=ldb,800x480M@60,if=RGB24 

video=mxcfb1:dev=hdmi,1920x1080M@60,if=RGB24

Kernel changes

enabled my LVDS panel channel@0. No other changes. 

Weston command for extended HDMI

$ weston --tty=1 --device=/dev/fb0,/dev/fb2 --use-g2d=1 &

Weston command for mirror HDMI

$ weston --tty=1 --device=/dev/fb0,/dev/fb2 --use-g2d=1 –clone-mode &

Note: 

1. make sure use-g2d=1 is enabled in /etc/xdg/weston/weston.ini 
2. To switch between extended and mirror, you need to restart the weston.

$ systemctl restart weston@root

[kaushalbisht2005]

U-Boot logo work fine. Need to enable the lvds_channel@0 in u-boot. Now if I select mxcfb0 as hdmi u-boot logo displayed in hdmi display.
If I select mxcfb0 as ldb, u-boot logo displayed in lvds display. How to achieve u-boot logo in both display simultaneously. There are so many question related to the same but no proper answer.

[Bio_TICFSL]

Hello kaushalbisht2005,

Please be aware this will only work with a uBoot version that pre-configures the HDMI PHY (ie. to show a splash screen).

At the end the idea is to use ipuo, di0 for both HDMI and LVDS0 so that the are mirrowed. In my case I configure the framebuffer using LVDS and just enable the HDMI PHY and connect it to the same DI as LVDS0.

Regards

[kaushalbisht2005]

Hi Bio_TICFSL,
Thanks for your reply. As per your comment,

"Please be aware this will only work with a uBoot version that pre-configures the HDMI PHY (ie. to show a 
splash screen)"
We are using u-boot version U-Boot 2016.01 (Jan 10 2022 - 09:05:20 +0000). Is this version 
per-configures the HDMI-PHY? if not, could you please share the patch or changes to do the same.

"In my case I configure the framebuffer using LVDS and just enable the HDMI PHY and connect it to 
the same DI as LVDS0."
Do you mean we need to configure the the HDMI core and lvds_channel@0 to ipo0,di0 in kernel thats all. I will we helpull
if you can share some more information.