device.detach_kernel_driver(0) - ERROR Could not detach kernel driver: [Errno 13] Access denied (insufficient permissions)

[jonnymoshiri]

Hello,

I have an issue running the following code, in my cloned github repo.

`from blinkstick import blinkstick

bstick = blinkstick.find_first()

#Set the color red on the 12th LED of R channel
bstick.set_color(channel=0, index=12, name="red")`

Specifically it fails in the call at find_first call. here is the full traceback.

Traceback (most recent call last):
File "/Users/jmoshiri/Documents/Repos/blinkstick-python/blinkstick/blinkstick.py", line 821, in open_device
self.device.detach_kernel_driver(0)
File "/Users/jmoshiri/Documents/Repos/blinkstick-python/venv/lib/python3.9/site-packages/usb/core.py", line 1075, in detach_kernel_driver
self._ctx.backend.detach_kernel_driver(
File "/Users/jmoshiri/Documents/Repos/blinkstick-python/venv/lib/python3.9/site-packages/usb/backend/libusb1.py", line 902, in detach_kernel_driver
_check(self.lib.libusb_detach_kernel_driver(dev_handle.handle, intf))
File "/Users/jmoshiri/Documents/Repos/blinkstick-python/venv/lib/python3.9/site-packages/usb/backend/libusb1.py", line 595, in _check
raise USBError(_strerror(ret), ret, _libusb_errno[ret])
usb.core.USBError: [Errno 13] Access denied (insufficient permissions)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/Users/jmoshiri/Documents/Repos/blinkstick-python/trial.py", line 4, in
bstick = blinkstick.find_first()
File "/Users/jmoshiri/Documents/Repos/blinkstick-python/blinkstick/blinkstick.py", line 1581, in find_first
return BlinkStick(device=d)
File "/Users/jmoshiri/Documents/Repos/blinkstick-python/blinkstick/blinkstick.py", line 215, in init
self.open_device(device)
File "/Users/jmoshiri/Documents/Repos/blinkstick-python/blinkstick/blinkstick.py", line 823, in open_device
raise BlinkStickException("Could not detach kernel driver: %s" % str(e))
blinkstick.blinkstick.BlinkStickException: Could not detach kernel driver: [Errno 13] Access denied (insufficient permissions)

I have given all the correct permissions in the set up for Blinkstick, and also given read write priveleges for all dependencies (usblib and pyusb) . My machine is running Mac OSx Big Sur and I am using Python 3.9.13. The only other way I was thinking to blinkstick via sudo priveleges either from the command line or from the IDE (pycharm in my case).

I got stumped at the command line priveleges in the set up because i do not have a directory udev in /etc for mac OS Big Sur

echo "SUBSYSTEM==\"usb\", ATTR{idVendor}==\"20a0\", ATTR{idProduct}==\"41e5\", MODE:=\"0666\"" | sudo tee /etc/udev/rules.d/85-blinkstick.rules

Any help is appreciated.

[dmingram66]

I've been looking at this on a Mac running Monterey on the arm64 architecture. Apple have a built in Kernel driver which does not need to be detached. I have commented out the call to self.open_device(device) on line 217 and the library still functions correctly. I'm trying to work out how to check if we are running on MacOS before suggesting a change to the library.

I do not advise running anything under sudo privileges, in any case the problem lies in an interaction between libusb and the operating system.

[dmingram66]

Here is a zip file containing a version which doesn't call open_device() if the platform is "macOS-12.6"

AppleSilicon.zip