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usb hotplug
#3
First examinations revealed the following fact

The devices in /dev/bus/usb/XXX/YYY follow naming policies in the Linux kernel. XXX is the bus number which is quite stable (001 in our case), but YYY changes (increased by 1) every time the USB device gets enumerated when a device just got inserted or reset. This cannot be changed and is part of the Linux kernel. So a device that initially was shown under /dev/bus/usb/001/006 for example will get /dev/bus/usb/001/007 after it is inserted back.

Now to the problem. When mapping a /dev/ into a container Docker makes a "snapshot" of the host /dev/ folder at the time the container is created and use it as reference when accessing it in a container. The problem is now that this folder structure it is not updated any more. So if a USB device is removed and inserted back the host /dev/ folder gets updated and shows the changes, but within a container the folder structure remains untouched. Hence it is not possible for the device's driver to find the device any more in a container and denies access.

We need more investigations how to solve this problem on netPI
You never fail until you stop trying.“, Albert Einstein (1879 - 1955)

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Messages In This Thread
usb hotplug - by Sven - February-13th-2019, 09:52 PM
RE: usb hotplug - by Armin@netPI - February-14th-2019, 12:43 PM
RE: usb hotplug - by Armin@netPI - February-18th-2019, 05:10 PM
RE: usb hotplug - by FrankJacob - March-29th-2019, 02:49 PM
RE: usb hotplug - by Armin@netPI - March-29th-2019, 07:37 PM

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