d2k17 Hackathon Report: Stefan Sperling on USB audio, WiFi Progress
by from OpenBSD Journal on (#2RJMM)
The first report from the recently completed d2k17 hackathon comes from Stefan Sperling, who writes:
This hackathon I took time to kick off a project I have been wantingto try for some time but never got around to: Adding sound support formy laptop which uses an internal USB audio device wired to xhci(4).Our xhci(4) driver lacks support for data transfers with guaranteed bandwidthand timing constraints (aka isochronous transfers). The first step is toadd support for such transfers (mpi@ tells me the rabbit hole ends up inuaudio(4) but I'll worry about that later). To get started, I spent sometime reading parts of the USB 2.0 and USB 3.1 specs, as well Intel's datasheet for the xHC interface (linked from https://en.wikipedia.org/wiki/XHCI).Equipped with this new knowledge, I started brushing up an old work-in-progressdiff that mpi@ shared with me. I did not make much progress and eventuallygot side-tracked into the wireless stack. But having finally explored thisproblem space feels good! I will try to keep exploring.
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