path: root/Documentation/IPMI.txt
diff options
authorCorey Minyard <>2006-12-06 20:41:07 -0800
committerLinus Torvalds <>2006-12-07 08:39:47 -0800
commitb361e27bba261ba59c73df464fa640f7c0fe3553 (patch)
tree4c457c471eb42be1fbcc9e76989e275fa8e023df /Documentation/IPMI.txt
parent15c62e10bb49eebf3da2b010a9196f5095947b0b (diff)
[PATCH] IPMI: system interface hotplug
Add the ability to hot add and remove interfaces in the ipmi_si driver. Any users who have the device open will get errors if they try to send a message. Signed-off-by: Corey Minyard <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'Documentation/IPMI.txt')
1 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/IPMI.txt b/Documentation/IPMI.txt
index 9101cbf2d883..24dc3fcf1594 100644
--- a/Documentation/IPMI.txt
+++ b/Documentation/IPMI.txt
@@ -365,6 +365,7 @@ You can change this at module load time (for a module) with:
+ unload_when_empty=[0|1]
Each of these except si_trydefaults is a list, the first item for the
first interface, second item for the second interface, etc.
@@ -416,6 +417,11 @@ by the driver, but systems with broken interrupts might need an enable,
or users that don't want the daemon (don't need the performance, don't
want the CPU hit) can disable it.
+If unload_when_empty is set to 1, the driver will be unloaded if it
+doesn't find any interfaces or all the interfaces fail to work. The
+default is one. Setting to 0 is useful with the hotmod, but is
+obviously only useful for modules.
When compiled into the kernel, the parameters can be specified on the
kernel command line as:
@@ -441,6 +447,25 @@ have high-res timers enabled in the kernel and you don't have
interrupts enabled, the driver will run VERY slowly. Don't blame me,
these interfaces suck.
+The driver supports a hot add and remove of interfaces. This way,
+interfaces can be added or removed after the kernel is up and running.
+This is done using /sys/modules/ipmi_si/hotmod, which is a write-only
+parameter. You write a string to this interface. The string has the
+ <op1>[:op2[:op3...]]
+The "op"s are:
+ add|remove,kcs|bt|smic,mem|i/o,<address>[,<opt1>[,<opt2>[,...]]]
+You can specify more than one interface on the line. The "opt"s are:
+ rsp=<regspacing>
+ rsi=<regsize>
+ rsh=<regshift>
+ irq=<irq>
+ ipmb=<ipmb slave addr>
+and these have the same meanings as discussed above. Note that you
+can also use this on the kernel command line for a more compact format
+for specifying an interface. Note that when removing an interface,
+only the first three parameters (si type, address type, and address)
+are used for the comparison. Any options are ignored for removing.
The SMBus Driver