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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.







    1. Thread and Zigbee use the same physical layer and MAC layer (IEEE 802.15.4), so in most case it can use the same hardware and just with different firmware (if manufacturer want).
      There is even a project to run both Zigbee coordinator and Thread border router on the same chip. It works! Although it causes some issue so Home Assistant no longer recommand this “multiprotocol” way, but this is a strong demonstration of the interchangeability between Zigbee and Thread.
    2. Thread Group members is almost the same companies who found Connectivity Standards Alliance (former Zigbee Alliance). When Connected Home over IP (CHIP) project was renamd to Matter at 2019, they create Thread Group to unify the home connectivity: Only use one network layer named IPv6 and one application layer named Matter. Zigbee can’t reach this target since it use its own network layer and application layer. So they invent Thread, which still based on IEEE 802.15.4, but with IPv6 as network layer and can transport Matter on it.



  • In anicent China, the writer and statesman Su Xun (蘇洵,苏洵) wrote a article named “On the Six Fallen States” (六國論, 六国论) about why the six states (韓、趙、魏、楚、燕、齊) were conquered by Qin (秦) during the Warring States period (戰國時代,战国时期)? The following is an excerpt from the relevant paragraph.

    今日割五城,明日割十城,然后得一夕安寝。
    One day five cities could be ceded, and on the next day, another ten cities could be surrendered just so that a certain person would have a single night of good sleep.
    起视四境,而秦兵又至矣。
    But in waking up and looking around, Qin troops again were approaching.
    然则诸侯之地有限,暴秦之欲无厌,奉之弥繁,侵之愈急。
    However, there was a limit to the available land of the lords and callous Qin’s avarice could never be satiated. The more there were giveaways, the more earnest Qin’s aggression would become.
    故不战而强弱胜负已判矣。
    So, even before going into battle, the odds-on-favorite and the most likely victor had already been decided.
    至于颠覆,理固宜然。
    As to the ultimate toppling, that was a forgone conclusion.
    古人云:“以地事秦,犹抱薪救火,薪不尽,火不灭。”
    Ancient people said: “Using land to serve Qin State would be like carrying firewood to put out fire. As long as there’s firewood left, the fire would not be extinguished.”

    In ancient, the six states use land to serve Qin state; in modern, the people use money to serve the companies provide subscription. The more people who pay for a subscription, the more power they have over price increases and control over your data.