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

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1

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?

2740-1920x720.png
2740-1920x720.png1348×805 72.6 KB

Convenient function “Device Tree Overlays” introduced from BSP5

2

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

3

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.

4

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”.

2743-1920x720.jpg
2743-1920x720.jpg2175×865 341 KB

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

5

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

6

Hi @alvaro.tx

Thank you. We look forward to.

7

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?

8

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.

9

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.