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-rw-r--r--Documentation/s390/CommonIO38
1 files changed, 20 insertions, 18 deletions
diff --git a/Documentation/s390/CommonIO b/Documentation/s390/CommonIO
index 8fbc0a85287..6e0f63f343b 100644
--- a/Documentation/s390/CommonIO
+++ b/Documentation/s390/CommonIO
@@ -8,20 +8,9 @@ Command line parameters
Enable logging of debug information in case of ccw device timeouts.
+* cio_ignore = device[,device[,..]]
-* cio_msg = yes | no
-
- Determines whether information on found devices and sensed device
- characteristics should be shown during startup or when new devices are
- found, i. e. messages of the types "Detected device 0.0.4711 on subchannel
- 0.0.0042" and "SenseID: Device 0.0.4711 reports: ...".
-
- Default is off.
-
-
-* cio_ignore = {all} |
- {<device> | <range of devices>} |
- {!<device> | !<range of devices>}
+ device := {all | [!]ipldev | [!]condev | [!]<devno> | [!]<devno>-<devno>}
The given devices will be ignored by the common I/O-layer; no detection
and device sensing will be done on any of those devices. The subchannel to
@@ -35,8 +24,10 @@ Command line parameters
device numbers (0xabcd or abcd, for 2.4 backward compatibility). If you
give a device number 0xabcd, it will be interpreted as 0.0.abcd.
- You can use the 'all' keyword to ignore all devices.
- The '!' operator will cause the I/O-layer to _not_ ignore a device.
+ You can use the 'all' keyword to ignore all devices. The 'ipldev' and 'condev'
+ keywords can be used to refer to the CCW based boot device and CCW console
+ device respectively (these are probably useful only when combined with the '!'
+ operator). The '!' operator will cause the I/O-layer to _not_ ignore a device.
The command line is parsed from left to right.
For example,
@@ -81,17 +72,29 @@ Command line parameters
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 reappears, it will then be ignored.
+ disappears and then reappears, it will then be ignored. To make
+ known devices go away, you need the "purge" command (see below).
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.accc and 0.0.af00-0.0.afff to the list of ignored
devices.
+ You can remove already known but now ignored devices via
+ "echo purge > /proc/cio_ignore"
+ All devices ignored but still registered and not online (= not in use)
+ will be deregistered and thus removed from the system.
+
The devices can be specified either by bus id (0.x.abcd) or, for 2.4 backward
compatibility, by the device number in hexadecimal (0xabcd or abcd). Device
numbers given as 0xabcd will be interpreted as 0.0.abcd.
+* /proc/cio_settle
+
+ A write request to this file is blocked until all queued cio actions are
+ handled. This will allow userspace to wait for pending work affecting
+ device availability after changing cio_ignore or the hardware configuration.
+
* For some of the information present in the /proc filesystem in 2.4 (namely,
/proc/subchannels and /proc/chpids), see driver-model.txt.
Information formerly in /proc/irq_count is now in /proc/interrupts.
@@ -109,8 +112,7 @@ debugfs entries
handling).
- /sys/kernel/debug/s390dbf/cio_msg/sprintf
- Various debug messages from the common I/O-layer, including messages
- printed when cio_msg=yes.
+ Various debug messages from the common I/O-layer.
- /sys/kernel/debug/s390dbf/cio_trace/hex_ascii
Logs the calling of functions in the common I/O-layer and, if applicable,