# HDMI output on A04 - disabled? **URL:** \ **Category:** DevTerm\ **Tags:** a04\ **Created:** [January 8, 2022, 11:34pm UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867 "2022-01-08T23:34:01Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![henryhu](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/henryhu/32/4456_2.png) [@henryhu](https://forum.clockworkpi.com/u/henryhu)\ **Post date:** [January 8, 2022, 11:34pm UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/1 "2022-01-08T23:34:01Z")
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? ---
**Author:** ![intelliarm](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/intelliarm/32/411_2.png) [@intelliarm](https://forum.clockworkpi.com/u/intelliarm)\ **Post date:** [January 13, 2022, 9:58pm UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/2 "2022-01-13T21:58:51Z")
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… ---
**Author:** ![Steve\_Engledow](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/steve_engledow/32/4811_2.png) [@Steve\_Engledow](https://forum.clockworkpi.com/u/Steve_Engledow)\ **Post date:** [January 13, 2022, 11:48pm UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/3 "2022-01-13T23:48:11Z")
I’m in the same boat and finding it strange that nobody from ClockworkPi has anything to say on this ☹ ---
**Author:** ![henryhu](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/henryhu/32/4456_2.png) [@henryhu](https://forum.clockworkpi.com/u/henryhu)\ **Post date:** [January 14, 2022, 2:26am UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/4 "2022-01-14T02:26:58Z")
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. ---
**Author:** ![adcockm](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/adcockm/32/1664_2.png) [@adcockm](https://forum.clockworkpi.com/u/adcockm)\ **Post date:** [January 14, 2022, 2:42am UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/5 "2022-01-14T02:42:43Z")
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. ---
**Author:** ![henryhu](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/henryhu/32/4456_2.png) [@henryhu](https://forum.clockworkpi.com/u/henryhu)\ **Post date:** [January 15, 2022, 12:55am UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/6 "2022-01-15T00:55:59Z")
So I tried to enable HDMI in the dts. It works a bit: ```auto [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: ```auto 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 ``` However: ```auto [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. ---
**Author:** ![henryhu](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/henryhu/32/4456_2.png) [@henryhu](https://forum.clockworkpi.com/u/henryhu)\ **Post date:** [January 15, 2022, 1:26am UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/7 "2022-01-15T01:26:34Z")
Then I disabled `tcon_lcd`, and sure enough, now the HDMI output works, but no LCD output. ---
**Author:** ![gvicino](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/gvicino/32/1618_2.png) [@gvicino](https://forum.clockworkpi.com/u/gvicino)\ **Post date:** [January 15, 2022, 7:53pm UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/8 "2022-01-15T19:53:58Z")
> [@henryhu](#): > > tcon\_tv Hi, I can ask you if you can kindly provide info about the procedure that you used? Thanks, Guido ---
**Author:** ![henryhu](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/henryhu/32/4456_2.png) [@henryhu](https://forum.clockworkpi.com/u/henryhu)\ **Post date:** [January 15, 2022, 8:01pm UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/9 "2022-01-15T20:01:05Z")
I’m playing with the device tree. I followed the procedures at [https://github.com/clockworkpi/DevTerm/tree/main/Code/patch/armbian\_build\_a04](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. ---
**Author:** ![henryhu](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/henryhu/32/4456_2.png) [@henryhu](https://forum.clockworkpi.com/u/henryhu)\ **Post date:** [January 15, 2022, 8:02pm UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/10 "2022-01-15T20:02:13Z")
Actually it might be simpler to use user-overlays ([Device Tree overlays - Armbian Documentation](https://docs.armbian.com/User-Guide_Allwinner_overlays/)) to override them. Just write some overlays to change the status fields and use `armbian-add-overlay` to apply them. ---
**Author:** ![gvicino](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/gvicino/32/1618_2.png) [@gvicino](https://forum.clockworkpi.com/u/gvicino)\ **Post date:** [January 15, 2022, 8:28pm UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/11 "2022-01-15T20:28:25Z")
Thank you!. I will try tomorrow morning to follow your suggestions! Very kind! ---
**Author:** ![henryhu](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/henryhu/32/4456_2.png) [@henryhu](https://forum.clockworkpi.com/u/henryhu)\ **Post date:** [January 16, 2022, 2:22am UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/12 "2022-01-16T02:22:40Z")
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. ---
**Author:** ![gvicino](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/gvicino/32/1618_2.png) [@gvicino](https://forum.clockworkpi.com/u/gvicino)\ **Post date:** [January 16, 2022, 1:11pm UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/13 "2022-01-16T13:11:15Z")
> [@henryhu](#): > > ddc-en-gpios Thank you for your thoughtfulness 🙂 You are right. I’m studying and reading the code/configuration before trying anything. I wrote also to [help@clockworkpi.com](mailto: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. ---
**Author:** ![darren.williams](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/darren.williams/32/5995_2.png) [@darren.williams](https://forum.clockworkpi.com/u/darren.williams)\ **Post date:** [January 20, 2022, 10:36pm UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/14 "2022-01-20T22:36:38Z")
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 😊 ---
**Author:** ![hobby\_grade](https://avatars.discourse-cdn.com/v4/letter/h/96bed5/32.png) [@hobby\_grade](https://forum.clockworkpi.com/u/hobby_grade)\ **Post date:** [January 25, 2022, 6:10pm UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/15 "2022-01-25T18:10:39Z")
I am no expert on the subject, but is the information about video posted on this page relevant at all? [Allwinner (Generic) - Armbian Documentation](https://docs.armbian.com/Hardware_Allwinner/) ---
**Author:** ![genbuckturgidson](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/genbuckturgidson/32/6148_2.png) [@genbuckturgidson](https://forum.clockworkpi.com/u/genbuckturgidson)\ **Post date:** [April 20, 2022, 3:02pm UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/16 "2022-04-20T15:02:22Z")
> [@henryhu](#): > > ```auto > > ``` Have you made any further progress? ---
**Author:** ![DoornailRumba](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@DoornailRumba](https://forum.clockworkpi.com/u/DoornailRumba)\ **Post date:** [May 22, 2023, 12:09am UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/17 "2023-05-22T00:09:47Z")
Any news with regard to the lack of HDMI on A04? (Apologies for resurrecting this old thread) ---
**Author:** ![Valssu](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/valssu/32/8026_2.png) [@Valssu](https://forum.clockworkpi.com/u/Valssu)\ **Post date:** [May 25, 2023, 2:28pm UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/18 "2023-05-25T14:28:46Z")
maybe never. I bought a CM4 modular. Will assemble that one tomorrow. ---
**Author:** ![henryhu](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/henryhu/32/4456_2.png) [@henryhu](https://forum.clockworkpi.com/u/henryhu)\ **Post date:** [December 29, 2024, 4:44am UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/19 "2024-12-29T04:44:29Z")
Aha, I’m checking my devTerm recently again, and after reading [https://www.kernel.org/doc/Documentation/devicetree/bindings/display/allwinner%2Csun8i-r40-tcon-top.yaml](https://www.kernel.org/doc/Documentation/devicetree/bindings/display/allwinner%2Csun8i-r40-tcon-top.yaml), I’m able to get HDMI+LCD working! Just put this into a file (such as hdmi.dts): ```auto /dts-v1/; /plugin/; / { compatible = "clockwork,devterm-a04"; fragment@0 { target = <&tcon_tv>; __overlay__ { status = "okay"; }; }; fragment@1 { target = <&i2s1>; __overlay__ { status = "okay"; }; }; fragment@2 { target = <&tcon_top>; __overlay__ { tcon_top_hdmi_in: port@4 { #address-cells = <1>; #size-cells = <0>; reg = <4>; tcon_top_hdmi_in_tcon_tv: endpoint@0 { reg = <0>; remote-endpoint = <&tcon_tv_out_tcon_top>; }; }; tcon_top_hdmi_out: port@5 { reg = <5>; tcon_top_hdmi_out_hdmi: endpoint { remote-endpoint = <&hdmi_in_tcon_top>; }; }; }; }; fragment@3 { target = <&tcon_tv_out_tcon_top>; __overlay__ { remote_endpoint = <&tcon_top_hdmi_in_tcon_tv>; }; }; fragment@4 { target = <&hdmi_in_tcon_top>; __overlay__ { remote_endpoint = <&tcon_top_hdmi_out_hdmi>; }; }; }; ``` Then run `sudo armbian-add-overlay hdmi.dts`, and reboot. Now it displays on both internal LCD and external HDMI! The main hint is this graph in that doc: ```auto / LCD0/LVDS0 / [0] TCON-LCD0 | \ MIPI DSI mixer0 | \ / [1] TCON-LCD1 - LCD1/LVDS1 TCON-TOP / \ [2] TCON-TV0 [0] - TVE0/RGB mixer1 | \ | TCON-TOP - HDMI | / \ [3] TCON-TV1 [1] - TVE1/RGB ``` Notice that the tcon-top goes to tcon-tv, then goes back to tcon-top, then goes to hdmi. This is reflected in the sample code below in the doc. In contrast, the default devterm devtree points the tcon-tv directly to hdmi. That’s incorrect. Once the connection is fixed, it works! Actually this is hinted by the aliases in the original device tree (for example, HDMI’s input endpoint is called hdmi\_in\_tcon\_top, hinting that it should come from tcon-top, not tcon-tv; also, tcon-tv’s output endpoint is called tcon\_tv\_out\_tcon\_top, hinting that it should go to tcon-top). I’m not sure why it’s not connected correctly. ---
**Author:** ![Toxya](https://yyz1.discourse-cdn.com/flex029/user_avatar/forum.clockworkpi.com/toxya/32/6034_2.png) [@Toxya](https://forum.clockworkpi.com/u/Toxya)\ **Post date:** [January 12, 2025, 1:12am UTC](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867/20 "2025-01-12T01:12:22Z")
It is so amazing!! Thank you so much!! I think everybody lost hope that it is possible. Just at the time I have ordered cm5 for HDMI capability on devterm. Now I will need to find another project for cm5, heh [Next page](https://forum.clockworkpi.com/t/hdmi-output-on-a04-disabled/7867.md?page=2)