chan_alloc: Change Channel Release to release SAPIs, then the channel

Currently every SAPI release indication will trigger the channel. It
was possible that we had SAPI=3 and SAPI=0 allocated and we tried to
release the channel by sending a RF Channel Release, the BTS answered
with a RF Channel Release ACK but also sent the SAPI Release Indication
which triggered a channel release here. So it was possible that we
would have released a newly allocated channel because of the SAPI
release of the old connection.

This code now works by releasing all SAPIs from highest to lowest,
then sending a SACH Deactivate and finally releasing the channel. This
approach is in use on the on-waves/bsc-master.
4 files changed
tree: 8c4110976d5024ef1275ce930ef661bcbc0ac940
  1. hlrsync/
  2. linux-kernel/
  3. openbsc/
  4. wireshark/