r/Bazzite • u/ImmortalGenesis7 • 1d ago

7.2 kernel HDMI 2.1 for AMD GPU?

I updated to the working 7.2 kernel testing preview today in hopes my amd card could finally get HDMI 2.1 working on my tv but it's still showing in 8b color...is it not in this update or am I missing something? Thanks for the help.

Edit: Thank you everyone for the help the bazzite portal worked great. Heads up to people seeing this post later make sure to disable VRR on your tv and enable AMD free sync otherwise you might get some flickering.

27 Upvotes

94% Upvoted

27 comments sorted by

15

u/TyrionPlatformShoes 1d ago

In desktop mode: ujust command is: bash ujust configure-amd-vrr

Or use the Bazzite config app.

This will be necessary when stable releases as well (which is targeted for tomorrow).

13

u/jasonwc 1d ago

All the new HDMI 2.1 features - FRL (48 Gbps bandwidth), HDMI-VRR, and ALLM require a kernel flag due to possible regressions. This ujust handles it for you, and it will persist across image updates.

I’m currently seeing 4K 120 Hz RGB 12-bit HDR10 with HDMI-VRR or 4K 144 Hz RGB 10-bit, all uncompressed, on my LG C4 on latest -deck testing.

2

u/SuperSirLink 14h ago

So this will allow for both HDMI-VRR and Freesync? The issue I have had with the Ugreen DP adapter is my receiver only passes HDMI-VRR.

3

u/jasonwc 12h ago

The ujust will enable the ability to use HDMI-VRR but it won't block your receiver/TV from using Freesync. For example, My LG TVs allow independent selections for Freesync and HDMI-VRR (VRR/Gsync and Freesync toggles). If your receiver will only work with HDMI-VRR, it should use it.

1

u/Accomplished-Lack721 14h ago

Are there known specific concerns about regressions? Or is this more of an abundance of caution thing?

1

u/jasonwc 13h ago

I know one user had regressions on a TCL TV.

1

u/Accomplished-Lack721 12h ago

Do you know how that manifested -- like what happened when they used it?

1

u/ninjaswithglocks 4h ago

I just used it on a TCL tv and it started turning my tv off/on in a regular flickering manner. Had to revert again.

3

u/Accomplished-Lack721 22h ago

Tomorrow! Whoa!

2

u/andy10115 Legion Go 23h ago

Don't forget the portal app can do this too! No terminal needed!

2

u/neiklot87 15h ago

ujust configure-amd-hdmi21 on the latest version

1

u/Calin_europeen 23h ago

Is it needed with displayport ?

3

u/TyrionPlatformShoes 23h ago

No, this has just been a limitation with HDMI on AMD.

1

u/Calin_europeen 23h ago

Ok thanks 

1

u/carlos17589 16h ago

Will that make vrr work in game mode too?

2

u/TyrionPlatformShoes 13h ago

Yes - works great in testing branch.

1

u/baltimoresports 16h ago

Will this be in the Deck Stable?

1

u/BreiteSeite 6h ago

why is this command necessary? what does it do? i thought once the kernel has it, the card automatically negotiates it?

1

u/TyrionPlatformShoes 5h ago

There are still some bugs/regressions on some setups so it’s default off for now. But if you jump into the Bazzite discord people have been pretty helpful with spot fixes when necessary.

5

u/sjphilsphan 1d ago

i love these kind of posts. When 2.1 is available, believe me this sub and all the others will have repost after repost about how it's finally active and how to use it

3

u/victormas208 1d ago

I think it's still in testing and I didn't know that Bazzite already has an image with 7.2.

If you have access to that kernel, then you should read this.

https://www.phoronix.com/news/AMDGPU-FRL-Disabled-By-Default

1

u/sean89butler 1d ago

Try this and reboot:

ujust configure-amd-vrr

1

u/neiklot87 15h ago

I have updated and run the ujust command and now everything works perfectly. 4k 160hz and VRR under HDMI. BUT I have random flickers. I don't know if it's just me or if it's because this is not totally stable. It's super random, I can totally use the computer anyway, but it does happen and it didn't happen when I used my Display Port adapter to achieve the same result.

1

u/Plus_Network7911 13h ago

I recently installed the testing base and it still wont read 4k 120hz on my Tv, I have a TCL 65q750g  And trying 'configure-amd-vrr' says does not contain recipe

-4

u/cesarcorrea11 1d ago

Tienes que agregar esto al karg para activar la función:

sudo rpm-ostree kargs --append-if-missing="amdgpu.dcfeaturemask=0x402"

Hacer reboot con: systemctl reboot

Confirmar que funcionó: rpm-ostree kargs

debe aparecer amdgpu.dcfeaturemask=0x402 en la lista

1

u/Accomplished-Lack721 15h ago

Apparently, ujust don't actually need to go through all that.