How to set a custom HDMI (DVI) resolution (1920x720) with the BSP5(Version: 5.x.y dunfell) "Device Tree Overlay"?

How to set a custom HDMI (DVI) resolution (1920x720) with the “Device Tree Overlay” that was BSP5? Is it possible to display with only the following simple changes?

Convenient function “Device Tree Overlays” introduced from BSP5
https://developer.toradex.com/knowledge-base/device-tree-overlays-linux#tab-colibri

Hi @takehito_yoshida , should be like that, yes. Have you tried?

Hi @alvaro.tx

Wow! It’s easy and good. I used to edit the kernel source directly.

I would like to rent a 1920x720 display and give it a try. I will report after confirmation.

Hi @alvaro.tx

It was a disappointing result. Even if the resolution is set to “1920x720” using “Device Tree Overlays”, it is output as “1920x1080”.

Attach the related boot-time dmesg.
[dmesg]

[ 0.275133] mxc_hdmi 20e0000.hdmi_video: 20e0000.hdmi_video supply HDMI not found, using dummy regulator

[ 0.275959] mxc_sdc_fb fb@0: NO mxc display driver found!

[ 0.276084] mxc_hdmi 20e0000.hdmi_video: Detected HDMI controller 0x13:0x1a:0xa0:0xc1

[ 0.276100] fbcvt: Aspect ratio not CVT standard
[ 0.276111] fbcvt: 1920x720@60: CVT Name - Not a CVT standard - 1.382 Mega Pixel Image

[ 0.276218] mxc_sdc_fb fb@1: registered mxc display driver hdmi

[ 0.288986] mxc_sdc_fb fb@1: 1920x1080 h_sync,r,l: 44,88,148 v_sync,l,u: 5,4,36 pixclock=148500000 Hz

[ 0.313556] imx-ipuv3 2400000.ipu: IPU DMFC DP HIGH RESOLUTION: 1(0,1), 5B(2~5), 5F(6,7)

[ 0.343797] mxc_hdmi 20e0000.hdmi_video: Read EDID again

[ 0.347478] mxc_sdc_fb fb@1: 1920x1080 h_sync,r,l: 44,88,148 v_sync,l,u: 5,4,36 pixclock=148500000 Hz

Thanks for the information. Let me check internally and I’ll get back to you.

Hi @alvaro.tx

Thank you. We look forward to.

Thanks for the information.

I checked a bit further and this resolution seems to not be added to the list of accepted resolutions by the EDID. My bad for not seeing this before.

https://git.toradex.com/cgit/linux-toradex.git/tree/drivers/video/fbdev/mxc/mxc_edid.c?h=toradex_4.9-2.3.x-imx#n41

Could you add it here, recompile the kernel and try again?

Dear @alvaro.tx

Thank you for answering. The new function “Device Tree Overlay” did not solve the problem, but it could be solved by updating the EDID list.

[upload|vmVJHJpHXTJ4vZotxRNqVh2QPwE=]

[upload|DjYBGGCqTNinYqJkHjCaWo4Kuv0=]

I like the new version because it’s easier to solve than the previous version. We will continue to conduct performance surveys in the future.

Thanks for the confirmation! Happy to see that it works this way. Standard resolutions are accepted thanks to EDID but in this case, EDID did not have 1920x720.