RE: libusb_open failed: LIBUSB_ERROR_ACCESS [page 76]. Possible solution.

Participant

Hi.

I changed the product ID in /etc/udev/rules.d/49-stlinkv2.rules from 3748 to 374b and now it seems to be working permanently.

You can find your vendor and product id with lsusb. Look for STMicroelectronics. ID <vendorID>:<productID>. Use these numbers (which are hexadecimal without prefix) in your 49-stlinkv2.rules file.

It would be great if someone could verify this.

/Martin

jhallier

Participant

I think it is correct. In my 60-openocd.rules, this was already set to this value (374b) and I did not have to change it, it worked.

I think the book is easy to misunderstand there. In the book, it reads

To do so, let us create a file named stlink.rules inside the /etc/udev/rules.d directory and add this line inside it:
$ sudo cp ~/STM32Toolchain/openocd/contrib/99-openocd.rules /etc/udev/rules.d/
$ sudo udevadm control –reload-rules

However, I don’t think we need to create any file, but just copy the 99-openocd.rules and once do the udevadm control –reload-rules after changing it in the current session, is this correct?

By the way, the file is called 60-openocd.rules in my case, does anyone know where this naming scheme comes from?

Thanks!