I did some tests and I found an interesting issue:
on the modem there are three usb port.. looking from the back, one in the upper left (where can be attached the data usb key), one in the edge of the lower and another on the edge of the right.
If I plug an usb drive in ther upper left port, I have this from the dmeg:
[ 432.559583] usb 2-1: new high-speed USB device number 2 using ifxusb_hcd
[ 432.760960] usb-storage 2-1:1.0: USB Mass Storage device detected
[ 432.770923] scsi host0: usb-storage 2-1:1.0
[ 433.849902] scsi 0:0:0:0: Direct-Access TDK LoR TF10 PMAP PQ: 0 ANSI: 4
[ 434.797023] sd 0:0:0:0: [sda] 15122432 512-byte logical blocks: (7.74 GB/7.21 GiB)
[ 434.804625] sd 0:0:0:0: [sda] Write Protect is off
[ 434.808031] sd 0:0:0:0: [sda] Mode Sense: 23 00 00 00
[ 434.809618] sd 0:0:0:0: [sda] No Caching mode page found
[ 434.813540] sd 0:0:0:0: [sda] Assuming drive cache: write through
[ 434.853763] sda: sda1
[ 434.868819] sd 0:0:0:0: [sda] Attached SCSI removable disk
so, it seems to work, but using the usb ports on the edge of the board, I see nothing on the dmesg.
looking at the dmesg, there are few differences from the 14.07 and 15.05:
from 15.05
[ 0.186422] usbcore: registered new interface driver usbfs
[ 0.192056] usbcore: registered new interface driver hub
[ 0.197479] usbcore: registered new device driver usb
[ 6.789902] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[ 6.812682] ehci-pci 0000:00:0f.2: new USB bus registered, assigned bus number 1
[ 6.835589] ehci-pci 0000:00:0f.2: USB 2.0 started, EHCI 1.00
[ 6.841916] hub 1-0:1.0: USB hub found
[ 6.853599] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[ 6.868678] uhci_hcd: USB Universal Host Controller Interface driver
[ 6.908941] IFXUSB: ifxusb_hcd: version 3.2 B110801
[ 7.416233] IFXUSB: USB core #0 soft-reset
[ 7.620144] IFXUSB: USB core #0 soft-reset
[ 7.622782] ifxusb_hcd ifxusb_hcd: IFX USB Controller
[ 7.627776] ifxusb_hcd ifxusb_hcd: new USB bus registered, assigned bus number 2
[ 7.634937] ifxusb_hcd ifxusb_hcd: irq 62, io mem 0xbe101000
[ 7.640378] IFXUSB: Mode Mismatch Interrupt: currently in Host mode
[ 7.646454] IFXUSB: Mode Mismatch Interrupt: currently in Host mode
[ 7.652541] IFXUSB: Init: Power Port (0)
[ 7.667230] hub 2-0:1.0: USB hub found
[ 7.674212] ifxusb_hcd ifxusb_hcd: requested GPIO 488
from the 14.07
[ 0.128000] usbcore: registered new interface driver usbfs
[ 0.132000] usbcore: registered new interface driver hub
[ 0.136000] usbcore: registered new device driver usb
[ 7.000000] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
[ 7.020000] ehci-pci 0000:00:0f.2: new USB bus registered, assigned bus number 1
[ 7.044000] ehci-pci 0000:00:0f.2: USB 2.0 started, EHCI 1.00
[ 7.048000] hub 1-0:1.0: USB hub found
[ 7.060000] ohci_hcd: USB 1.1 'Open' Host Controller (OHCI) Driver
[ 7.068000] uhci_hcd: USB Universal Host Controller Interface driver
[ 7.080000] uhci_hcd 0000:00:0f.0: new USB bus registered, assigned bus number 2
[ 7.092000] hub 2-0:1.0: USB hub found
[ 7.104000] uhci_hcd 0000:00:0f.1: new USB bus registered, assigned bus number 3
[ 7.120000] hub 3-0:1.0: USB hub found
[ 7.132000] IFXUSB: ifxusb_hcd: version 3.2 B110801
[ 7.640000] IFXUSB: USB core #0 soft-reset
[ 7.844000] IFXUSB: USB core #0 soft-reset
[ 7.848000] ifxusb_hcd ifxusb_hcd: IFX USB Controller
[ 7.852000] ifxusb_hcd ifxusb_hcd: new USB bus registered, assigned bus number 4
[ 7.860000] ifxusb_hcd ifxusb_hcd: irq 62, io mem 0xbe101000
[ 7.864000] IFXUSB: Mode Mismatch Interrupt: currently in Host mode
[ 7.868000] IFXUSB: Mode Mismatch Interrupt: currently in Host mode
[ 7.876000] IFXUSB: Init: Power Port (0)
[ 7.880000] hub 4-0:1.0: USB hub found
[ 7.888000] ifxusb_hcd ifxusb_hcd: requested GPIO 232
[ 7.900000] usbcore: registered new interface driver usb-storage
[ 9.328000] usb 3-2: new full-speed USB device number 2 using uhci_hcd
I have no more ideas. It seems something releated to the kernel.
Cheers,
Angelo