This introduces support for loading multiple firmwares in parallel also
for the case of a manual load. This is anyway the case for an automatic
load from udev.
* libusb needs to scan the bus all too often. This causes occasional
failures for opening devices.
* Thus introduce a semaphore to serialize uses of libusb.
E-Main-3 firmware differs by a different value of bcdDevice:
* Read this from the sysfs devices tree.
* Fall back to lsusb -v (much slower) is sysfs not available.
Signed-off-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>
git-svn-id: http://svn.astersk.org/svn/dahdi/tools/trunk@10348 17933a7a-c749-41c5-a318-cba88f637d49
e6c2b1850d