mirror of
https://github.com/t2linux/apple-bce-drv.git
synced 2026-08-15 20:18:35 -07:00
Jeff Johnson
c7448ca0a5
PLAYBACK used dev_timestamp from the T2 coprocessor clock domain, which drifts from the host's ktime_get_boottime() after module reload. This produced wild position values in aaudio_pcm_pointer, triggering XRUN and a scheduling-while-atomic panic when snd_pcm_do_stop ran from DMA IRQ context. Switch PLAYBACK to os_timestamp (host boottime at message receipt), matching what CAPTURE already does. The mailbox transit delay (~100 microseconds at most) is negligible in a 347 ms ALSA buffer and eliminates the crash entirely.
MacBook Bridge/T2 Linux Driver
A driver for MacBook models 2018 and newer, implementing the VHCI (required for mouse/keyboard/etc.) and audio functionality.
The project is divided into 3 main components:
- BCE (Buffer Copy Engine) - this is what the files in the root directory are for. This estabilishes a basic communication channel with the T2. VHCI and Audio both require this component.
- VHCI - this is a virtual USB host controller; keyboard, mouse and other system components are provided by this component (other drivers use this host controller to provide more functionality, however USB drivers are not in this project's scope).
- Audio - a driver for the T2 audio interface, currently only audio output is supported.
Please note that the master branch does not currently support system suspend and resume.
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