path: root/Documentation
diff options
Diffstat (limited to 'Documentation')
2 files changed, 15 insertions, 1 deletions
diff --git a/Documentation/ABI/testing/sysfs-driver-st b/Documentation/ABI/testing/sysfs-driver-st
new file mode 100644
index 000000000000..ba5d77008a85
--- /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
+ 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.
diff --git a/Documentation/scsi/st.txt b/Documentation/scsi/st.txt
index f29fa550665a..b3211af63b79 100644
--- a/Documentation/scsi/st.txt
+++ b/Documentation/scsi/st.txt
@@ -569,7 +569,9 @@ Debugging code is now compiled in by default but debugging is turned off
with the kernel module parameter debug_flag defaulting to 0. Debugging
can still be switched on and off with an ioctl. To enable debug at
module load time add debug_flag=1 to the module load options, the
-debugging output is not voluminous.
+debugging output is not voluminous. Debugging can also be enabled
+and disabled by writing a '0' (disable) or '1' (enable) to the sysfs
+file /sys/bus/scsi/drivers/st/debug_flag.
If the tape seems to hang, I would be very interested to hear where
the driver is waiting. With the command 'ps -l' you can see the state

Privacy Policy