I'm trying to connect a serial device with Webusb, under linux.
I have been able to list the device and open it, but I can't claim the interface. Chrome complains that the device is busy, and to fix that I need to unregister the CDC-ACM driver.
Is there a way to prevent the CDC-ACM driver from loading the device, without changes on the destkop? maybe I can change the USB descriptors?
If you can change the device descriptors then modify the protocol, class and sub-class reported by the CDC-ACM interface so that it is marked as vendor-specific (0xff). The CDC-ACM driver will no longer recognize the interface and bind to it.
Just for completeness, if you could make changes to the desktop then you can either blacklist the usb-serial driver entirely in /etc/modprobe.d/blacklist or you could write a udev rule which runs for that device in particular (recognized be either bus path or vendor and product ID) and executes a script to unbind the driver.