USB Mass Storage Gadget can't find UDC

octopus12345 · 10-01-2015, 08:54 AM

Hi Guys!

I am trying to access the storage area of rootfs partition to a PC through USB Device Mode.

I would like to turn the mmcblk0p2 into a gadget_mass_storage device.

My target is a Marvell Kirkwood platorm. I am using mainline Kernel 4.2.1.

I'm able to include the Marvell USB2.0 Device Controller functionality as a module (<M>):

[root@(none) ~]# modprobe mv_udc
[root@(none) ~]# lsmod
Module Size Used by
mv_udc 18658 0

However when I try to loading the module g_mass_storage I get:

[root@(none) ~]# modprobe g_mass_storage file=/root/backing_file
FATAL: Error inserting g_mass_storage (/lib/modules/4.3.0-rc3-00040-g097f70b-dirty/kernel/drivers/usb/gadget/legacy/g_mass_storage.ko): No such device

I realized that displaying the dmesg the following message appear when I trying to load g_mass_storage through modprobe:

couldn't find an available UDC

I'm really stucked into something that it seems some people has had success so i might be missing something.
Any suggestions are welcome.

Thanks in advance.

octopus12345 · 10-02-2015, 09:24 AM

Bump!

I think that mv_udc_probe() function in driver mv_udc is never called. When I use dummy_hcd module it seems to work fine, however I can't use any other driver.
Can anybody say me where is a bug or suggest any workaround?