I cannot get HDMI CEC to work on the Framework Desktop (with Bazzite). I remember the spec sheet mentioning CEC support when I ordered, but now it is not there anymore.
Was anyone able to get it to work?
AFAIK you need the adapter since I haven’t seen ANY pc’s that support hdmi cec natively.
As of current, there is no support for HDMI-CEC, but the Framework Desktop IS wired up internally to support it eventually.
Based on the open source schematics, the CEC is wired up to the EmbeddedController so in the future Framework could totally program it to power on/power off with a TV via HDMI; but at this time I didn’t see any code using the HDMI CEC pins.
References:
EmbeddedController/zephyr/program/framework/dogwood/gpio.dtsi at ad0db6aab83c208a6fd001ad81180069109e3839 · FrameworkComputer/EmbeddedController · GitHub (Search gpio_ec_cec)
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Valve has announced that its new Steam Machine will support HDMI CEC. I hope whatever they are doing will push HDMI CEC forward to become a common feature on Linux HTPCs, including the FW Desktop.
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You can actually get HDMI CEC working on any Linux PC that has DisplayPort right now. That’s because DisplayPort 1.3 supports transporting CEC messages over the auxiliary channel. So a suitable DisplayPort-to-HDMI adapter will work for CEC, even if the native HDMI port doesn’t.
Unfortunately the “suitable” part is doing a lot of heavy lifting here. The cheap “passive” ones used for DisplayPort Dual-Mode will never work for CEC. You need an “active” adapter that uses a chip that supports CEC. These are known to work (pay attention to the model numbers!):
- CD0712: Active DP to HDMI Adapter 4K@60Hz | CableCreation
- CAC-1080: DisplayPort™ 1.4 to HDMI™ 2.0b HDR Active Adapter | Club3D
On Framework laptops, the HDMI Expansion Card also supports CEC, since the USB-C ports support DisplayPort Alt Mode.
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It is a shame we don’t know which gpio on the EC it is connected to. It is only about 20 lines of C code to implement it.
Add an ectool command for the CEC message.
Bitbang the command out of the gpio.
Receiving commands from the hdmi device/TV is a little more difficult, but you probably don’t need that initially.
Unless you wish to switch on the PC from a tv remote control.
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This is sick. I never knew that, thou I’ve been recently interested in CEC and did some research on it.
Once again HDMI sucks and DisplayPort rules.
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I didn’t have any luck with that one in the past on my 9060 XT.
iirc either somewhere in the Kernel logs or the Arch wiki there was a mention that Club3D changed the circuitry or the chip during the lifespan on the 1080 adapter.
So may be down to luck/lottery with that one.
That said: I today purchased an Ugreen “8K” DP 1.4 → HDMI 2.1 adapter and that one not only survived 4k120 HDR 4:4:4 during reboots and cold boots (something the CableMatter adapter could never do on any firmware) but also had HDMI CEC Info on my Sony Bravia 8 during Bazzite boot (but lost HDMI-CEC once the system was booted). No HDMI-VRR though either.
I’ll need to investigate this adapter further, not sure which chipset it uses but it it 9€ on the big A..
Signed up just to throw my 2 cents in here. Of the support is in the hardware for the hdmi port already, I would love to see support for this enabled. It would be a huge value add for “steam machine” -like use cases, or for folks using an lg OLED tv as their main display.
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Club3D’s own spec sheet specifically mentions “CEC Support - snooping, tunneling” as one of its features, so that is very surprising. I would consider it a defect on Club3D’s part.
I have the CableCreation’s CD0712, and I can personally confirm that its CEC implementation works.
DisplayPort dual-mode only works up to around HDMI 1.4, so passive adapters only work up to 1440p60. Any DP→HDMI adapter that claims HDMI 2.1 support has to be an active adapter, which would explain why their CEC works even if they don’t advertise as such.
DisplayPort alt mode on USB-C does not support dual-mode at all. So all USB-C→HDMI adapters are active adapters and might support CEC.
I remember reading somewhere that the reference designs for the converter chips in the past didn’t connect the CEC pin, so it didn’t work even on active adapters. This has probably been fixed in the reference designs for newer chips, so CEC support amongst HDMI adapters nowadays could be more common than I initially thought.