Usb devices and kernel modules auto-loading

Marco Vittorini Orgeas marco at mavitt.org
Mon Jan 23 15:30:46 UTC 2012


Hi list,

I'm on Fedora 16 and trying to solve a problem with an usb device(a CP2103 
based device) which doesn't get recognized by the system, even if the linux 
driver already supports it at 99%: 

the problem seems to be that CP210x based devices have vendor programmable 
device IDs and if the device is not being detected is likely because the 
device IDs are unknown (http://www.etheus.net/CP210x_Linux_Driver).

Now it would seems that adding my device id(which is not present at the moment 
in the latest kernel module) could solve the problem, thus I've modified the 
source of the driver and I've successfully locally compiled it following 
http://www.cyberciti.biz/tips/build-linux-kernel-module-against-installed-
kernel-source-tree.html.

I have issued a "sudo modprobe CP210x" to load the CP210x module, and it loads 
fine, but the dmesg output shows the kernel doesn't still recognize the device 
when I plug it.

I guess my problem is the linux kernel while using an auto-loading (hot-
plugging?) feature to auto-load usb modules, is still referring to the stock 
CP210x module included with the kernel source tree instead of mine and this 
prevent it to successfully recognize the device as supported.

I've tried searching around for info about the auto-loading mechanism and how 
to pin inside it, but I've found an overwhelming amount of text which does not 
explain where (and how) the kernel search for its available drivers.

Would somebody point me to the right direction and clear how the kernel manage 
usb modules auto-loading in latest fedora or add just some hint?

thank you,

	Marco 




More information about the users mailing list