2 files changed, 8 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index d29b6d926a42..880f882160e2 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -370,6 +370,9 @@ and is between 256 and 4096 characters. It is defined in the file
                         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 86320aa3fb0b..8fbc0a852870 100644
--- a/Documentation/s390/CommonIO
+++ b/Documentation/s390/CommonIO
@@ -4,6 +4,11 @@ S/390 common I/O-Layer - command line parameters, procfs and debugfs entries
 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