No Audio with kms driver. Screen tearing with fkms driver.

[levitatingGuru]

I’m looking for a fix for one of these two problems. I get screen tearing with fkms pretty bad towards the bottom of my screen. Kms works great and fixes this but I’m guessing the hdmi audio drivers aren’t compatible? Audio just keeps resetting to 0 volume. I appreciate any feedback

[Ashpool]

@levitatingGuru If you are using a TV as a display, can you simply try it with a different one?

I had' a similar problem whence switching on one of my pi4 from jezzy to 64bit buster: it showed no audio card at all with the default kms, with fkms everything was fine - sadly I can't find the threats/posts again I had found in those time (maybe +-~ a year ago?), but somewhere during my searches (and don't take my words here as a real explanation, not without requestioning them) I've found something along the lines that with kms enabled, the hdmi-audio had to be/is interleaved with the video-mode in a different way as it is with fkms and that some displays/modes may cause problems. Haven't found a workaround since then apart from either falling back to fkms or, what I finally had done, to replace the tv in question with another one that worked (no changes on the pi-/install-part, just exchanging the tv).

To be honest I had intented to replace the older one since 2019/2020 [as it also had some minor problems with its edid-information] but always was to lazy to build the proper side-shelf/mount for the allready owned replacement-tv to my computer-desktop (as it had a larger base/size then the previous tv), so after trying it 1st and, after I found out that it worked OOB, to finally streighten up and getting the needed jigsaw and drill-work done. Maybe your problem is different from the one I had experienced, but if not I am really interested in the a "how it could have worked for the previous tv"-solution (if there is any)!

[7ank0v1c]

@levitatingGuru Hey, I am wondering how you went about installing the kms driver? I am trying to also resolve the screen tearing but can't figure it our for the life of me. I have adapted the config.txt but I have read I have to install the KMS kernel 5.4 or something like that? is that correct?