wm: doc

Download patch

ref: aaa542d877d1d1dfb5f9be7d98af7bf962739228
parent: e0833d4c9f144090b4d527307683983351ce0dbc
author: mkf <mkf@cloud9p.org>
date: Tue Aug 20 01:33:00 EDT 2024

pi.ms: document state of USB in pi

--- a/pi.ms
+++ b/pi.ms
@@ -66,6 +66,15 @@
 source code for wireless driver is available in
 .CW /sys/src/9/bcm/ether4330.c
 .NH
+USB
+.LP
+It's widely believe before raspberry pi 4 (that includes zero 2), they had nasty USB controllers,
+while they may (is there a case otherwise?) work well for keyboard, mouses and thumb drives,
+they may not work as well as expected for devices that need more power.
+.LP
+Also note that, USB controller can crash (is it a hardware limit?) if it gets too hot,
+using a heat sink and fan is recommended if you are you are going to use that raspberry pi's USB (which sadly, also includes ethernet, since it uses USB).
+.NH
 UART
 .NH
 Compiling a kernel