Weird "call trace" error - 4.7

Saw this tonight on my system:

Apr 24 00:47:01 Tower kernel: ------------[ cut here ]------------
Apr 24 00:47:01 Tower kernel: WARNING: at drivers/ata/libata-core.c:5186 ata_qc_
issue+0x10b/0x308()
Apr 24 00:47:01 Tower kernel: Hardware name: TA870U3+
Apr 24 00:47:01 Tower kernel: Modules linked in: md_mod xor r8169 ahci sata_mv m
vsas libsas scst scsi_transport_sas
Apr 24 00:47:01 Tower kernel: Pid: 28641, comm: hdparm Not tainted 2.6.32.9-unRA
ID #8
Apr 24 00:47:01 Tower kernel: Call Trace:
Apr 24 00:47:01 Tower kernel:  [<c102449e>] warn_slowpath_common+0x60/0x77
Apr 24 00:47:01 Tower kernel:  [<c10244c2>] warn_slowpath_null+0xd/0x10
Apr 24 00:47:01 Tower kernel:  [<c11b624d>] ata_qc_issue+0x10b/0x308
Apr 24 00:47:01 Tower kernel:  [<c11ba260>] ata_scsi_translate+0xd1/0xff
Apr 24 00:47:01 Tower kernel:  [<c11a816c>] ? scsi_done+0x0/0xd
Apr 24 00:47:01 Tower kernel:  [<c11a816c>] ? scsi_done+0x0/0xd
Apr 24 00:47:01 Tower kernel:  [<c11baa40>] ata_sas_queuecmd+0x120/0x1d7
Apr 24 00:47:01 Tower kernel:  [<c11bc6df>] ? ata_scsi_pass_thru+0x0/0x21d
Apr 24 00:47:01 Tower kernel:  [<f843569a>] sas_queuecommand+0x65/0x20d [libsas]
Apr 24 00:47:01 Tower kernel:  [<c11a816c>] ? scsi_done+0x0/0xd
Apr 24 00:47:01 Tower kernel:  [<c11a82c0>] scsi_dispatch_cmd+0x147/0x181
Apr 24 00:47:01 Tower kernel:  [<c11ace4d>] scsi_request_fn+0x351/0x376
Apr 24 00:47:01 Tower kernel:  [<c1126798>] __blk_run_queue+0x78/0x10c
Apr 24 00:47:01 Tower kernel:  [<c1124446>] elv_insert+0x67/0x153
Apr 24 00:47:01 Tower kernel:  [<c11245b8>] __elv_add_request+0x86/0x8b
Apr 24 00:47:01 Tower kernel:  [<c1129343>] blk_execute_rq_nowait+0x4f/0x73
Apr 24 00:47:01 Tower kernel:  [<c11293dc>] blk_execute_rq+0x75/0x91
Apr 24 00:47:01 Tower kernel:  [<c11292cc>] ? blk_end_sync_rq+0x0/0x28
Apr 24 00:47:01 Tower kernel:  [<c112636f>] ? get_request+0x204/0x28d
Apr 24 00:47:01 Tower kernel:  [<c11269d6>] ? get_request_wait+0x2b/0xd9
Apr 24 00:47:01 Tower kernel:  [<c112c2bf>] sg_io+0x22d/0x30a
Apr 24 00:47:01 Tower kernel:  [<c112c5a8>] scsi_cmd_ioctl+0x20c/0x3bc
Apr 24 00:47:01 Tower kernel:  [<c11b3257>] sd_ioctl+0x6a/0x8c
Apr 24 00:47:01 Tower kernel:  [<c112a420>] __blkdev_driver_ioctl+0x50/0x62
Apr 24 00:47:01 Tower kernel:  [<c112ad1c>] blkdev_ioctl+0x8b0/0x8dc
Apr 24 00:47:01 Tower kernel:  [<c1131e2d>] ? kobject_get+0x12/0x17
Apr 24 00:47:01 Tower kernel:  [<c112b0f8>] ? get_disk+0x4a/0x61
Apr 24 00:47:01 Tower kernel:  [<c101b028>] ? kmap_atomic+0x14/0x16
Apr 24 00:47:01 Tower kernel:  [<c11334a5>] ? radix_tree_lookup_slot+0xd/0xf
Apr 24 00:47:01 Tower kernel:  [<c104a179>] ? filemap_fault+0xb8/0x305
Apr 24 00:47:01 Tower kernel:  [<c1048c43>] ? unlock_page+0x18/0x1b
Apr 24 00:47:01 Tower kernel:  [<c1057c63>] ? __do_fault+0x3a7/0x3da
Apr 24 00:47:01 Tower kernel:  [<c105985f>] ? handle_mm_fault+0x42d/0x8f1
Apr 24 00:47:01 Tower kernel:  [<c108b6c6>] block_ioctl+0x2a/0x32
Apr 24 00:47:01 Tower kernel:  [<c108b69c>] ? block_ioctl+0x0/0x32
Apr 24 00:47:01 Tower kernel:  [<c10769d5>] vfs_ioctl+0x22/0x67
Apr 24 00:47:01 Tower kernel:  [<c1076f33>] do_vfs_ioctl+0x478/0x4ac
Apr 24 00:47:01 Tower kernel:  [<c105dcdd>] ? do_mmap_pgoff+0x232/0x294
Apr 24 00:47:01 Tower kernel:  [<c1076f93>] sys_ioctl+0x2c/0x45
Apr 24 00:47:01 Tower kernel:  [<c1002935>] syscall_call+0x7/0xb
Apr 24 00:47:01 Tower kernel: ---[ end trace 4e4724d9e543603b ]---

Anyone have a clue what this means? Tower looks fine... everything up...

Shawn