On 01/11/2012 07:44 PM, Alan Stern wrote:
On Wed, 11 Jan 2012, Sebastian Andrzej Siewior wrote:
* Alan Stern | 2012-01-11 12:11:57 [-0500]:
On Wed, 11 Jan 2012, Sebastian Andrzej Siewior wrote:
Well no. Even if you override it in kernel the user still could switch
it if he wants to.
How? If usb-storage refuses to bind to devices that support UAS, the
user has no way to force it to bind.
I meant if UAS does not work _or_ he prefers BOT, he can still switch
back to BOT.
How can the user switch back to BOT if usb-storage refuses to bind?
In case both configs are available and are working and the user prefers
BOT over UAS he could switch back. Assume that usb-storage does not
refuse to bind.
Felipe, what is Nokia and the other people that have the multi-
functional gadgets use to switch from one function to the other?
Do those gadgets use separate _altsettings_ for BOT vs. UAS, or do they
use separate _configs_?
They have both. Both configs provide the same functions, if you look at
lsusb of the g_multi gadget:
...
The listing shows two configs: one for CDC + RNDIS and mass storage
BOT, the other for CDC ECM and mass storage BOT. There's nothing about
UAS.
So you need a tool to switch between storage, CDC ....
I don't understand. Why can't you use CDC and storage at the same
time?
I though you can only use _one_ Interface at a time. Hmmm. So I loaded
the g_multi driver. After that I loaded manually the storage driver and
was able to access /dev/sda. Next thing I did was loading the network
driver and I got usb0 and usb1. I set the ip address. After that I tried
to access dev/sda again and it hung:
[ 157.672942] usbcore: registered new interface driver cdc_ether
root@squsb:~# hexdump -C /dev/sda | head
[ 216.804125] cdc_ether 1-1:2.0: forced unbind
[ 216.804735] dummy_hcd dummy_hcd: shutdown urb deba5db0 ep3in-intr
[ 216.808351] cdc_ether 1-1:2.0: usb1: unregister 'cdc_ether'
usb-dummy_hcd-1, CDC Ethernet Device
[ 216.904273] hub 1-0:1.0: state 7 ports 1 chg 0000 evt 0002
[ 216.960175] usb 1-1: reset high-speed USB device number 2 using dummy_hcd
[ 217.020186] hub 1-0:1.0: state 7 ports 1 chg 0000 evt 0002
[ 217.124086] gadget: high-speed config #2: Multifunction with CDC ECM
This went for a while and then it ended with:
[ 254.459129] sd 0:0:0:0: Device offlined - not ready after error recovery
[ 254.461439] sd 0:0:0:0: rejecting I/O to offline device
[ 254.462150] sd 0:0:0:0: rejecting I/O to offline device
[ 254.462996] sda: unable to read partition table
That makes me think that I can not use two of those at the same time.
But I can use one of them at a time.
Alan Stern
Sebastian
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