HDMI output on A04 - disabled?

It seems like that tcon_tv is disabled in dts, and it’s in charge of HDMI output.Are there still some problems to be resolved for HDMI output?


any new findings? I also don’t have hdmi output on my A04.
I wanted but haven’t got time to check dts or kernel configs. It’s strange since H6 processor is targeted at TV box market…

I’m in the same boat and finding it strange that nobody from ClockworkPi has anything to say on this :frowning:

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I bet it would not be hard to have HDMI output only (i.e., no LCD, which is the case for TV boxes etc.).
It might be trickier to get HDMI + LCD working.

Just FYI, on A06 HDMI output works either as an extended display in addition to the LCD, or as a mirror. I’m not sure there’s a way to turn off the LCD completely, though it’s possible to turn the backlight off by turning it all the way down.

It’s concerning that clockworkpi folks haven’t responded to the A04 HDMI issue as it seems to be a consistent problem among all A04 owners.


So I tried to enable HDMI in the dts.

It works a bit:

[    2.905678] sun4i-drm display-engine: Adding to iommu group 0
[    2.925324] sun4i-drm display-engine: bound 1100000.mixer (ops 0xffff800010e15520)
[    2.926445] sun4i-drm display-engine: bound 1200000.mixer (ops 0xffff800010e15520)
[    2.926736] sun4i-drm display-engine: bound 6510000.tcon-top (ops 0xffff800010e19930)
[    2.927090] sun4i-drm display-engine: bound 6515000.lcd-controller (ops 0xffff800010e10660)
[    2.927595] sun4i-drm display-engine: bound 6511000.lcd-controller (ops 0xffff800010e10660)
[    2.927683] sun8i-dw-hdmi 6000000.hdmi: supply hvcc not found, using dummy regulator
[    2.928130] sun8i-dw-hdmi 6000000.hdmi: Detected HDMI TX controller v2.12a with HDCP (DWC HDMI 2.0 TX PHY)
[    2.928966] sun8i-dw-hdmi 6000000.hdmi: registered DesignWare HDMI I2C bus driver
[    2.929396] sun4i-drm display-engine: bound 6000000.hdmi (ops 0xffff800010e14858)

and it shows up in xrandr:

Screen 0: minimum 320 x 200, current 2304 x 768, maximum 8192 x 8192
None-1 connected 1280x480+1024+0 right (normal left inverted right x axis y axis) 0mm x 0mm
   480x1280      59.30*+
HDMI-1 connected primary 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
   1024x768      60.00*
   800x600       60.32    56.25
   848x480       60.00
   640x480       59.94


[   32.269389] sun50i-iommu 30f0000.iommu: Page fault for 0x00000000ff0b3000 (master 0, dir rd)
[   33.169591] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[   37.313264] sun50i-iommu 30f0000.iommu: TLB Flush timed out!
[   37.329252] sun50i-iommu 30f0000.iommu: TLB Flush timed out!
[   37.392009] sun50i-iommu 30f0000.iommu: TLB Flush timed out!

and neither the internal screen nor the HDMI output works.
There are driver problems to be resolved, I guess.

Then I disabled tcon_lcd, and sure enough, now the HDMI output works, but no LCD output.


I can ask you if you can kindly provide info about the procedure that you used?


I’m playing with the device tree. I followed the procedures at https://github.com/clockworkpi/DevTerm/tree/main/Code/patch/armbian_build_a04, and changed the patches to the dts file.
In userpatches/kernel/sunxi-current/kernel_001_dts.patch, notice that tcon_tv has its status set to “disabled”, and i2s1 is not enabled as well. They can be changed “okay”. To disable tcon_lcd, set its status to “disabled”.
I also commented out the “ddc-en-gpios” field in hdmi-connector. I’m not sure if that’s set correctly.
In general, I’m very new to embedded development, so I’m not sure if this is the correct procedure. It would be better to change the source directly, instead of changing the patches, I think. Changing the patch is tricky.

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Actually it might be simpler to use user-overlays (Device Tree overlays - Armbian Documentation) to override them. Just write some overlays to change the status fields and use armbian-add-overlay to apply them.

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Thank you!. I will try tomorrow morning to follow your suggestions! Very kind!

Well, notice that changing the configuration can be dangerous, and it may destroy the hardware components. I’m not suggesting that these are the proper config to use; I’m still experimenting with it.

Thank you for your thoughtfulness :slight_smile: You are right. I’m studying and reading the code/configuration before trying anything.

I wrote also to help@clockworkpi.com to report the issue and highlight your post as useful one to investigate the topic.

Thanks again and have a nice sunday.

I had an A04 arrive with a dead screen. Support asked me to plug in to HDMI but I got no output. They then said that this is a problem, and a fix is coming.
I now have a new screen, and everything that side is fine, just waiting for the HDMI fix :blush:


I am no expert on the subject, but is the information about video posted on this page relevant at all? Allwinner (Generic) - Armbian Documentation

Have you made any further progress?