[S390] cio: Dump ccw device information in case of timeout.

Information about a ccw device will be dumped in
case of a ccw timeout. This can be enabled with
the kernel parameter ccw_timeout_log.

Signed-off-by: Sebastian Ott <sebott@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index d29b6d9..880f882 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -370,6 +370,9 @@
 			configured.  Potentially dangerous and should only be
 			used if you are entirely sure of the consequences.
 
+	ccw_timeout_log [S390]
+			See Documentation/s390/CommonIO for details.
+
 	checkreqprot	[SELINUX] Set initial checkreqprot flag value.
 			Format: { "0" | "1" }
 			See security/selinux/Kconfig help text.
diff --git a/Documentation/s390/CommonIO b/Documentation/s390/CommonIO
index 86320aa..8fbc0a8 100644
--- a/Documentation/s390/CommonIO
+++ b/Documentation/s390/CommonIO
@@ -4,6 +4,11 @@
 Command line parameters
 -----------------------
 
+* ccw_timeout_log
+
+  Enable logging of debug information in case of ccw device timeouts.
+
+
 * cio_msg = yes | no
   
   Determines whether information on found devices and sensed device