[PATCH 4.2.y-ckt 058/273] libata: fix sff host state machine locking while polling

4.2.8-ckt5 -stable review patch. If anyone has any objections, please let me know. ---8< From: Tejun Heo commit 8eee1d3ed5b6fc8e14389567c9a6f53f82bb7224 upstream. The bulk of ATA host state machine is implemented

[PATCH 4.2.y-ckt 058/273] libata: fix sff host state machine locking while polling

4.2.8-ckt5 -stable review patch. If anyone has any objections, please let me know. ---8< From: Tejun Heo commit 8eee1d3ed5b6fc8e14389567c9a6f53f82bb7224 upstream. The bulk of ATA host state machine is implemented by