tree e923e6f55126c25b2411462748435ca882bf0027
parent 64821324ca49f24be1a66f2f432108f96a24e596
author Peter Oberparleiter <peter.oberparleiter@de.ibm.com> 1154001623 +0200
committer Martin Schwidefsky <schwidefsky@de.ibm.com> 1154001623 +0200

[S390] permanent subchannel busy conditions may cause I/O stall

In special conditions where a subchannel rejects the HALT I/O-
instruction with a busy indication (cc 2), I/O may stall.
I/O request termination logic retries HALT I/O indefinitely
because it expects HALT I/O to alter the subchannel status which
is not true when cc 2 is returned.
In case of a busy indication, try CLEAR I/O instruction immediately.

Signed-off-by: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>