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authorCornelia Huck <cornelia.huck@de.ibm.com>2006-12-08 17:56:02 +0300
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2006-12-08 17:56:02 +0300
commit7f090145a14afc35844dce80174c9c24f9e66ec5 (patch)
tree14ee3ba84574ed147ea779c2747d4bec2cc72915 /Documentation/s390/driver-model.txt
parent529192f3b90682e37c5fcab461d968d062f1e0e4 (diff)
downloadlinux-7f090145a14afc35844dce80174c9c24f9e66ec5.tar.xz
[S390] Update documentation for dynamic subchannel mapping.
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'Documentation/s390/driver-model.txt')
-rw-r--r--Documentation/s390/driver-model.txt7
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/s390/driver-model.txt b/Documentation/s390/driver-model.txt
index 77bf450ec39b..e938c442277d 100644
--- a/Documentation/s390/driver-model.txt
+++ b/Documentation/s390/driver-model.txt
@@ -18,11 +18,18 @@ devices/
- 0.0.0002/
- 0.1.0000/0.1.1234/
...
+ - defunct/
In this example, device 0815 is accessed via subchannel 0 in subchannel set 0,
device 4711 via subchannel 1 in subchannel set 0, and subchannel 2 is a non-I/O
subchannel. Device 1234 is accessed via subchannel 0 in subchannel set 1.
+The subchannel named 'defunct' does not represent any real subchannel on the
+system; it is a pseudo subchannel where disconnnected ccw devices are moved to
+if they are displaced by another ccw device becoming operational on their
+former subchannel. The ccw devices will be moved again to a proper subchannel
+if they become operational again on that subchannel.
+
You should address a ccw device via its bus id (e.g. 0.0.4711); the device can
be found under bus/ccw/devices/.