kernel: ahcich1: Timeout on slot 0 port 0

[Ivan Klymenko]

Hello all
After the upgrade, with a revision r255868 to revision r255882
I have the following problem:
.....
Sep 27 12:49:01 nonamehost kernel: ahcich1: Timeout on slot 0 port 0
Sep 27 12:49:01 nonamehost kernel: ahcich1: is 00000000 cs 00000001 ss 00000000 rs 00000001 tfd d0 serr 00000000 cmd 0000c017
Sep 27 12:49:01 nonamehost kernel: ahcich1: Timeout on slot 0 port 0
Sep 27 12:49:01 nonamehost kernel: ahcich1: is 00000000 cs 00000001 ss 00000000 rs 00000001 tfd d0 serr 00000000 cmd 0000c017
Sep 27 12:49:01 nonamehost kernel: ahcich1: Timeout on slot 0 port 0
Sep 27 12:49:01 nonamehost kernel: ahcich1: is 00000000 cs 00000001 ss 00000000 rs 00000001 tfd d0 serr 00000000 cmd 0000c017
Sep 27 12:49:01 nonamehost kernel: ahcich1: Timeout on slot 0 port 0
Sep 27 12:49:01 nonamehost kernel: ahcich1: is 00000000 cs 00000003 ss 00000000 rs 00000003 tfd d0 serr 00000000 cmd 0000c017
......
many messages

In what could be the reason?

FreeBSD 10.0-ALPHA3 #0 r255882

Thank you.