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Cake day: June 26th, 2023

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  • He may want to say “fastsync” (whose kernel part called winesync). It’s the predecessor of NTsync and was renamed to NTsync when merged into linux mainline.

    Before NTsync was merged, those distrobutions provides the kernel packages with winesync patches. Since linux 6.12, NTsync was merged so they droped winesync from kernel package. But NTsync’s API is different with fastsync/winesync, so old wine with fastsync support will stop working with new kernel. (While NTsync still isn’t merged to wine)



  • In fact, most manufacturers save money and don’t shield the cable, forcing half-speed USB 1.1, which is enough for all mice and keyboards - less than 50 kb/s of the available 6 Mb/s is required even for 240Hz polling. High-end mice might have USB 3.0 (9 pins instead of 4 in the plug) but there should be no practical difference between 3.0 and 2.0 speeds.

    When speed is enough, latency became an issue. Although with 8kHz poll rate (USB 2.0 half-speed and full-speed can only get 1kHz poll rate), the latency will be 125µs at least. But for USB 3.0, it gained two ways to improve latency: 1) it can send Bus Interval Adjustment Message to adjust latency to 13.333µs (around 75kHz); 2) it can switch to async mode. Host no longer poll the device, instead, the device notify host via ERDY.

    Of course, I don’t know how many devices utilized these features.