path: root/Documentation/s390
diff options
authorCornelia Huck <>2005-06-21 17:16:27 -0700
committerLinus Torvalds <>2005-06-21 19:07:33 -0700
commit6fd6e4a44ff9ff406bcff69050b508f186507df1 (patch)
tree224b28914a10b8c17b57df60624e0f94366a51b8 /Documentation/s390
parent5bdfcfcc0780f58b927a164dfd54d1e1b6767347 (diff)
[PATCH] s390: cio documentation
Some clarifications in the cio documentation. Signed-off-by: Martin Schwidefsky <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'Documentation/s390')
1 files changed, 9 insertions, 7 deletions
diff --git a/Documentation/s390/CommonIO b/Documentation/s390/CommonIO
index a831d9ae5a5e..59d1166d41ee 100644
--- a/Documentation/s390/CommonIO
+++ b/Documentation/s390/CommonIO
@@ -30,7 +30,7 @@ Command line parameters
device numbers (0xabcd or abcd, for 2.4 backward compatibility).
You can use the 'all' keyword to ignore all devices.
The '!' operator will cause the I/O-layer to _not_ ignore a device.
- The order on the command line is not important.
+ The command line is parsed from left to right.
For example,
@@ -72,13 +72,14 @@ Command line parameters
/proc/cio_ignore; "add <device range>, <device range>, ..." will ignore the
specified devices.
- Note: Already known devices cannot be ignored.
+ Note: While already known devices can be added to the list of devices to be
+ ignored, there will be no effect on then. However, if such a device
+ disappears and then reappeares, it will then be ignored.
- For example, if device 0.0.abcd is already known and all other devices
- 0.0.a000-0.0.afff are not known,
+ For example,
"echo add 0.0.a000-0.0.accc, 0.0.af00-0.0.afff > /proc/cio_ignore"
- will add 0.0.a000-0.0.abcc, 0.0.abce-0.0.accc and 0.0.af00-0.0.afff to the
- list of ignored devices and skip 0.0.abcd.
+ will add 0.0.a000-0.0.accc and 0.0.af00-0.0.afff to the list of ignored
+ devices.
The devices can be specified either by bus id (0.0.abcd) or, for 2.4 backward
compatibilty, by the device number in hexadecimal (0xabcd or abcd).
@@ -98,7 +99,8 @@ Command line parameters
- /proc/s390dbf/cio_trace/hex_ascii
Logs the calling of functions in the common I/O-layer and, if applicable,
- which subchannel they were called for.
+ which subchannel they were called for, as well as dumps of some data
+ structures (like irb in an error case).
The level of logging can be changed to be more or less verbose by piping to
/proc/s390dbf/cio_*/level a number between 0 and 6; see the documentation on