auto-dismount fake CD (was Re: Android device problems with MTP ID)

[Lowell Gilbert]

Hans Petter Selasky <hselasky at c2i.net> writes:

> On Thursday 03 January 2013 20:58:15 Lowell Gilbert wrote:
>> Hans Petter Selasky <hselasky at c2i.net> writes:
>> > On Thursday 03 January 2013 20:34:50 Lowell Gilbert wrote:
>> >> On my (updated to Android 4.1.1) phone, MTP only works if the phone's
>> >> USB debugging option is enabled. If it is, usbconfig(8) sees a ugen(4)
>> >> interface of MTP type; but otherwise it just shows up as a CD device.
>> > 
>> > Try to use cdcontrol to eject the CD.
>> 
>> Thanks! That works! [And I can see the logic behind it, even, from a
>> firmware point of view.]
>> 
>> I should be able to automate the eject command through devd, I think.
>> It would be nice to put something in the tree that would do that, but
>> being sure not to catch cases you'd want such a feature would be
>> error-prone.
>> 
>> I'll move forward on making MTP more convenient on FreeBSD. A lot of
>> devices are starting to force it on us, and it keeps the device usable
>> while the computer is accessing its files.
>> 
>> Thanks again!
>> 
>> Be well.
>>         Lowell
>
> There might be a quirk for that.
>
> See usbconfig, and send a patch for that if you figure it out :-)

I was wrong about being able to do this in userland; devd doesn't have
the device name, and devfs doesn't have enough information to identify
the disk as being bogus (as well as not currently having a mechanism to
do anything to the device except ownership/permissions/etc.).

So I guess a quirk would be the best way to do it, and I don't see any
existing functionality that even resembles this.  Is this something that
would be worth my while to create? 

I wouldn't mind writing it if it were generally useful, but I don't know
for a fact that anyone else would want to use it. A scheme flexible
enough to have a hope of working with future devices would be
substantially more complicated than I need for my own purposes, so I'd
like to know if anyone else would want it also.

Thanks,
       Lowell