Jay's some notes

Ubuntu 19.10 Intel wireless-ac 9560 driver exception重启电脑后发现wifi不能使用了，网络设置里面提示未发现网络适配器。电脑比较新，之前安装ubuntu18.10 低版本kernel 版本就发现不识别wifi设备，更新到ubuntu19.10 后正常，不过正常安装后也反复重启过使用了一段时间。Detected Intel(R) Wireless-AC 9560, REV=0x354；Ubuntu 19.10 5.3.0-40-generic；小米笔记本pro 15；排查第一时间排查dmesg 发现有iwlwifi 内核模块报错。主动搜...

目录 [隐藏]I. kernel driverII. sunxi watchdogIII. force fsckIV. troubleshooting linux watchdog基于debian8 的linux设备会低概率的出现的系统完整死机，这里思考给linux添加完整的看门狗策略。debian8已经采用systemd用以初始化系统和守护、管理系统进程。这里同时存在systemd 的watchdog和keepalive 单元文件，以及sysv init的watchdog keepavlie 初始化脚本，同时systemd也直接看门狗启动，那么该如何选择呢？syste...

a64 gpio interrupt init failed如下pc0，gpio64 设置中断触发边沿失败。~$ tree /sys/class/gpio/gpio64/ ├── active_low ├── device -> ../../../1c20800.pinctrl ├── direction ├── power │   ├── async │   ├── autosuspend_delay_ms │   ├── control │   ├── runtime_active_kids │   ├── runtime_active_time │   ├── runtime...

目录 [隐藏]I. IntroductionII. Structure of a driverIII. Structure of the frameworkstruct v4l2_devicestruct v4l2_subdevstruct video_devicestruct v4l2_fhV4L2 events Overview of the V4L2 driver frameworkThis text documents the various structures provided by the V4L2 framework and their relations...

gpio对linux c app里面的一个gpio操作云里雾里半天，是时候好好理理了。https://www.kernel.org/doc/Documentation/gpio/sysfs.txthttps://www.kernel.org/doc/Documentation/gpio/gpio-legacy.txt主要是这gpio number是如何同pin number 一一对应的。256 root@mxj-zbcs-310:#tree /sys/class/gpio . |-- export |-- gpio120 -> ../../devices/soc.0/1c20800...

目录 [隐藏]I. allwinner h6II. allwinner a63III. hi3798 docsIV. vp9 decoder test vp9 decoder cpu summary这里系统了解全志和海思的解码能力。I. allwinner h6https://pan.baidu.com/s/1aA-jRLSWtjaUq6BhXxq8mw em4jhttp://linux-sunxi.org/H6从Allwinner_H6_V200_User_Manual_V1.1_decrypted->Chapter 2 Overview->2.2.6....

目录 [隐藏]I. thermal sensorII. governorIII. cooling deviceIV. test script linux cooling device这里详细介绍并理解基于 allwinner a64 linux 下根据热量传感器 采集的温度用以自动调频 原理。I. thermal sensorhttp://linux-sunxi.org/Thermal_Sensora64集两个热量传感器分别监控gpu和cpu温度。The thermal sensors have become common elements in wide range...