On Wed, Aug 9, 2017 at 9:25 AM, Bjørn Mork <bjorn@xxxxxxx> wrote: > loïc tourlonias <loic.tourlonias@xxxxxxxxx> writes: Thank's for the quick response > >> Hi everybody, >> >> In my project I have an USB composite device (a LTE modem) which use >> USB to communicate with the processor. This device has several >> interface to communicate but I do not use all of them. In particular, >> it loads cdc_ether device which I don't use and I have an undesired >> ethXX which interferes with a service in my system. > > Sounds like your system has other issues, but whatever... I may not have been clear in my explanation. What seems wrong with my system? > >> To schematize, let's say my device is loaded on port 2 of usb1, I have >> the following USB topology: >> - 1-2:1.0: tty >> - 1-2:1.1: tty >> - 1-2:1.2: tty >> - 1-2:1.3: tty >> - 1-2:1.4: tty >> - 1-2:1.5: eth (not desired) >> >> Is there a way to prevent this specific ethXX to mount? >> >> I've already tried to create a udev rules, but I don't manage to stop >> the loading process. >> Here is a summary of my tries: >> 1/ I couldn't use the /sys/bus/usb1/.../1-2/activated file in my udev >> rule because it's an USB composite device and I want to use the tty >> interfaces but not the eth interface >> >> 2/ I have tried to stop the udev loading process, but setting MODALIAS >> environment variable to a NULL-string doesn(t do the trick and >> last-rule udev option has been removed in my udev version (1.8.2). >> >> 3/ I have tried to create a custom environment variable IGNORE_ETH and >> modify my last rule which run modprobe with the modalias variable. In >> the logs I see that modprobe isn't called by udev rules, but the >> cdc_ether device is loaded all the same. >> >> 4/ I have think of creating a stub cdc_ether driver and use the >> /etc/modprobe.d/my_file.conf to preempt the loading for my specific >> usb composite device but this solution is ugly and I'm not sure it >> will work. > > The cdc_ether driver treats any ID entry with .driver_info = 0 as a > blacklist entry. So you can dynamically blacklist devices by writing > the "VID PID" to /sys/bus/usb/drivers/cdc_ether/new_id before the device > is probed. > I have tried this and look at the source code of driver/usb/core/driver.c. But I think this is not what I required. What I understand is that the new_id file is used to dynamically add new USB id to the cdc_ether driver. What I want is the opposite, currently my device is loaded with cdc_ether.ko and I want this device to remain unloaded. Furthermore, after sending this email I have thought of renaming my device in an udev rule. But unfortunately, it passed by an eth0 state which I want to get rid of. > > Bjørn _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
