wifi error for raspberry: brcmfmac: brcmf_set_channel: set chanspec 0x100e fail, reason -52

 

I couldn't connect to my raspberry pi for several days. Today I conducted a trouble shooting. 

At beginning, I think system is down due to flashcard broken but later I found raspyberry still has ipv4/ipv6 address from home router. I tried to ssh but not successful. I ping the server first, ping is Ok. Then I could ssh server successfully.

it seems i am not the only guy who has this issue, see 

https://forums.raspberrypi.com/viewtopic.php?t=367466

https://askubuntu.com/questions/1508490/ubuntu-server-on-raspberry-pi-5-is-not-connecting-to-the-internet

python typing check

• Docstring Linter
• pydocstyle
• Style Linter
• pylint
• pycodestyle
• Error Linter: 
• pyflake
• pylint
• Complexity Analysis
• mccabe 
• flake8
• flake8 = Pyflakes + pycodestyle + mccabe
• type checker: 
• mypy
• run it on command line
• run it with language server, for example: pylsp
• run it with Jupyter
• nb-mypy: configure it with ipython configuration or run it with command in jupyter
•  jupyter-lsp + pylsp
• Language server
• pyls and pylsp
• prefer to use pylsp instead of pyls, see link for detail.
• difference between different linter tools
• Pylint vs Pyflakes vs Flake8 vs autopep8 vs Bandit vs Prospector vs Pylama vs Pyroma vs Black vs Mypy vs Radon vs mccabe

racket

 racket is one of scheme dialect and I want to use racket to learn "the litte schemer". One of problem I meet is how to load file with scheme code (not racket code) into REPL and run relate function. In guile, it is very simple: guile -l my_function.scm. but in racket, it is little complex.

• with load (traditional scheme file, no #lang)

 it could work "racket -if <my_function.scm>" but my_function.scm should not start with "#lang racket". it is same with load function. 

• with module (racket file, with #lang)

Racket has concept of module, every file is module and each module need "initial-module-path" which is "The #lang at the start of a module file begins a shorthand for a module form"

First, like import in python, you could use (require my_function.scm) in source code and "-t " in command line to import a module, but you need to list which function is export by (provide function) in my_function.scm, or (provide (all-defined-out)) to export all functions. 

 -t <file>, --require <file> Like -e '(require (file "<file>"))' [*]

Another trick point is you need "racket -i -t my_function.scm" instead of "racket -t  my_function.scm -i". I don't know why but I guess it is related to "If -t/-l/-p/-u appears before the first -i/-e/-f/-r, -n is added".

Second, you could config initial-module in command line with "racket -I typed/racket" (#lang typed/racket in source code). The magic of of initial-module-path is you could define a new language with different syntax.

Third, you could always start "racket -i" and use ",enter my_function.scm" or "racket -i -e '(enter! "my_function.scm")'" to go to my_function namespace.

git remote repository with bare

 if you want a remote repository and put local source into remote, you need to set up remote repository with  "git init bare . ", not "git init ."

link1, link2

xmlrpc on rtorrent

rotorrent could use xmlrpc to send command remotely without any ui interface.

• how to setup xmlrpc support (link, link2 )
• configure scgi port on rtorrent.rc
• install nginx and setup location for scgi and configure same scgi port from rtorrent.rc
• rtorrent from Archlinux has dependency (libxmlrpc from http://xmlrpc-c.sourceforge.net/). there is binary application in this package to send xmlrpc command to rtorrent
• xmlrpc basic
• xmlrpc is specification for request sent to client (link)
• xmlrpc has scalar (int,boolean, string, double), struct (dictionary), array. 
• xmlrpc binary command convert command parameter into request. Different binary command has different command parameter but request is same.
• for xmlrpc (http://xmlrpc-c.sourceforge.net/), it need to escape ":" as "\:" since ":" is separator for struct. (link ). The parenthesis, brace, comma, colon, and backslash characters are special. If you want to include one in a string value, escape it with a backslash.
• usag
• "2838954B0BBB1A87A668308DCC08AAF56D83D20D" is infohask for one rtorrent.
• "2838954B0BBB1A87A668308DCC08AAF56D83D20D\:t0" is tracker1 for one rtorrent.
• 
  
• xmlrpc localhost system.listMethods
• xmlrpc localhost system.methodHelp t.id
• xmlrpc localhost load.normal "magnet:?xt=urn:btih:59066769B9AD42DA2E508611C33D7C4480B3857B&dn=ubuntu-17.04-desktop-amd64.iso&tr=http%3A%2F%2Ftorrent.ubuntu.com%3A6969%2Fannounce&tr=http%3A%2F%2Fipv6.torrent.ubuntu.com%3A6969%2Fannounce"
• 
  
• xmlrpc localhost download_list
• xmlrpc localhost d.is_open 2938964B0BAB1A87A668308DCC08AAF56D83C20D
• xmlrpc localhost d.state <hash>
• xmlrpc localhost d.chunk_size 2838954B0BBB1A87A668308DCC08AAF56D83D20D
• xmlrpc localhost d.size_files  "BBAB39AF48A4BD6FD23F1CCA39246A3E9D22F76B"
• xmlrpc localhost d.size_chunks  "BBAB39AF48A4BD6FD23F1CCA39246A3E9D22F76B"
• xmlrpc localhost d.size_bytes  "BBAB39AF48A4BD6FD23F1CCA39246A3E9D22F76B"
• xmlrpc localhost d.completed_chunks  "BBAB39AF48A4BD6FD23F1CCA39246A3E9D22F76B"
• xmlrpc localhost d.complete 2838954B0BBB1A87A668308DCC08AAF56D83D20D
• 
  
• xmlrpc localhost d.ratio 2838954B0BBB1A87A668308DCC08AAF56D83D20D
• xmlrpc localhost d.down.total 2838954B0BBB1A87A668308DCC08AAF56D83D20D
• xmlrpc localhost d.down.rate 2838954B0BBB1A87A668308DCC08AAF56D83D20D
• xmlrpc localhost d.up.total 2838954B0BBB1A87A668308DCC08AAF56D83D20D
• xmlrpc localhost d.up.rate 2838954B0BBB1A87A668308DCC08AAF56D83D20D
• 
  
• xmlrpc localhost p.multicall 2838954B0BBB1A87A668308DCC08AAF56D83D20D p.id
• 
  
• xmlrpc localhost d.tracker.insert 2838954B0BBB1A87A668308DCC08AAF56D83D20D 0 "udp\://tracker.openbittorrent.com\:80"
• xmlrpc localhost d.tracker.insert 2838954B0BBB1A87A668308DCC08AAF56D83D20D 1 "udp\://tracker.opentrackr.org\:1337/announce"
• xmlrpc localhost d.tracker_size 2838954B0BBB1A87A668308DCC08AAF56D83D20D
• xmlrpc localhost t.id <hash>
• xmlrpc localhost t.is_open "2838954B0BBB1A87A668308DCC08AAF56D83D20D\:t1"
• xmlrpc localhost t.id "2838954B0BBB1A87A668308DCC08AAF56D83D20D\:t0"
• 
  
• xmlrpc localhost f.multicall  "BBAB39AF48A4BD6FD23F1CCA39246A3E9D22F76B"  "*"  f.path=
• xmlrpc localhost f.frozen_path "BBAB39AF48A4BD6FD23F1CCA39246A3E9D22F76B\:f2"
• xmlrpc localhost f.path "BBAB39AF48A4BD6FD23F1CCA39246A3E9D22F76B\:f3"
• xmlrpc localhost f.completed_chunks "BBAB39AF48A4BD6FD23F1CCA39246A3E9D22F76B\:f2"
• xmlrpc localhost f.size_bytes "BBAB39AF48A4BD6FD23F1CCA39246A3E9D22F76B\:f2"

WSL with gpu accelerator and webgpu

GPU accelerator on WSL need WDDM 2.9 (link ). Windows 10 support WDDM from 20H2 (link) but Intel driver only support WDDM > 2.9 from Windows 11 (link). You could use "dxdiag" to check WDDM version on your windows.

My laptop is Intel GPU + Windows 10. Intel driver doesn't support WDDM v2.9 or later on Windows 10 but it is OK on Windows 11. It means WSL couldn't support GPU accelerator on Windows 10.

If you want to use webgpu under wsl2, use following chrome command since webgpu on chrome only support vulkan now according to Chrome ships WebGPU. 

• "--enable-unsafe-webgpu --enable-features=Vulkan --use-vulkan=swiftshader" 
• "This initial release of WebGPU is available in Chrome 113 on ChromeOS devices with Vulkan support, Windows devices with Direct3D 12 support, and macOS. Linux, Android, and expanded support for existing platforms will come soon."

GCC

some tips when i trying compile opengl programs in conda

• g++ -I/home/hongy19/miniconda3/envs/opengl/include/ : include *.h
• g++ -L/home/hongy19/miniconda3/envs/opengl/lib   :add folder of *.so for link(ld)
• g++ -lglfw: use libglfw.so for link(ld)
• LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/home/hongy19/miniconda3/envs/opengl/lib ./a.out: add library search path for dynamic *.so 
• static compile
• -static compile for static link need *.a and *.o library and *.so doesn't work for static compile, see link.  The error of following code is due to missing of *.a or *.o even *.so existed.
  

(opengl) hongy19@WSL opengl$ gcc glfw-1.cpp -static -lglfw -lGL
/usr/sbin/ld: cannot find -lglfw: No such file or directory
/usr/sbin/ld: cannot find -lGL: No such file or directory
collect2: error: ld returned 1 exit status

• pkgconfig
• PKG_CONFIG_PATH=$CONDA_PREFIX/lib/pkgconfig pkg-config --list-all
• PKG_CONFIG_PATH=$CONDA_PREFIX/lib/pkgconfig pkg-config --cflags glfw3 -I/home/hongy19/miniconda3/envs/opengl/include
• PKG_CONFIG_PATH=$CONDA_PREFIX/lib/pkgconfig pkg-config --cflags  gtk+-3.0

X11 and wayland

 

see Environment variables for Wayland hackers and Wayland-specific environment variables for detail and what is setting in wsl2.

• WAYLAND_DISPLAY
• wayland unix socket
• WAYLAND_DISPLAY=wayland-0
• XDG_RUNTIME_DIR
• directory of wayland unix socket
• XDG_RUNTIME_DIR=/mnt/wslg/runtime-dir/ or XDG_RUNTIME_DIR=/run/user/1000/
• DISPLAY
• X11 unix socket
• DISPLAY=:0 and /tmp/.X11-unix/X0
• GDK_BACKEND
• it is better to set according to GTK backend selection, or why GTK cannot open display: :0
• If the special value of help is used, a GTK application will print the possible values it knows. see link.

gtk3/gtk3 in conda has disabled wayland support, see link.  

• with pygobject, GDK_BACKEND=wayland doesn't work but chrome/weston-terminal is OK and pygobject is OK with GDK_BACKEND=wayland, x11 or GDK_BACKEND=x11. 
• with GDK_BACKEND=help, gtk3 only support x11, not wayland
• condas gtk3.0/gtk4.0 only support x11, not wayland since no  ~/miniconda3/envs/gtk/include/gtk-3.0/gdk/gdkwayland.h.

  (gtk) hongy19@WSL cairo$ GDK_BACKEND=help python test1.py

  Supported GDK backends: x11