v4.19.13 snapshot.
diff --git a/Documentation/ABI/testing/sysfs-driver-st b/Documentation/ABI/testing/sysfs-driver-st
new file mode 100644
index 0000000..ba5d770
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-st
@@ -0,0 +1,12 @@
+What: /sys/bus/scsi/drivers/st/debug_flag
+Date: October 2015
+Kernel Version: ?.?
+Contact: shane.seymour@hpe.com
+Description:
+ This file allows you to turn debug output from the st driver
+ off if you write a '0' to the file or on if you write a '1'.
+ Note that debug output requires that the module be compiled
+ with the #define DEBUG set to a non-zero value (this is the
+ default). If DEBUG is set to 0 then this file will not
+ appear in sysfs as its presence is conditional upon debug
+ output support being compiled into the module.