Comment 14 for bug 1239087

OK, I just made that change

 http://cgit.freedesktop.org/udisks/commit/?id=fcdd8f48b6ac9b1b6da82fdf5f59230fc2ea6feb

and tested it with a couple of different units. Notes

 - One of my devices (bus-powered) does not accept the START STOP UNIT
   command so we just continue if it fails. That is, this patch should
   not break existing behavior.

 - Another device (not bus-powered) used to spin down a couple of seconds
   after removing power to the USB port. With this patch it spins down
   immediately. (Which is actually nicer.)

 - Still works on USB sticks etc.

 - I didn't add SCSI SYNCHRONIZE CACHE as that command failed on all my
   devices. I also don't think it's necessary as the device drivers will
   issue something like this in part of the fsync(2) call that we do
   before this.

Please test if the patch works and report back - thanks!