Asahi Linux progress report [LWN.net]

Asahi Linux progress report

Posted Mar 16, 2021 12:32 UTC (Tue) by pizza (subscriber, #46)
In reply to: Asahi Linux progress report by farnz
Parent article: Asahi Linux progress report

Well, HDA does provide an interface to set the "protected bit" of SP/DIF outputs.

But so did every AC97 codec that supported SP/DIF output, so that's hardly a regression.

(I think my first kernel contribution was a patch enabling that feature for various Crystal Semi codecs -- The receiver I was trying to use refused to accept data that didn't have that bit set, and forcing it on was enough to get it working...)

to post comments

Asahi Linux progress report

Posted Mar 16, 2021 12:52 UTC (Tue) by farnz (subscriber, #17727) [Link]

It also has a set of verbs defined to confirm HDCP is in place before sending audio, but there's no standard way to encrypt the audio on a HDA link, just as there's no standard way to encrypt the audio on an AC97 link. And there's no standard way to do HDMI audio on AC97 at all, so the fact that HDCP can be checked in a standard fashion on HDA is neither here nor there - any AC97 audio implementation would do the same.