ipmi: add new kernel options to prevent automatic ipmi init

The configuration change building ipmi_si into the kernel precludes the use of a custom driver that can utilize more than one KCS interface, multiple IPMBs, and more than one BMC. This capability is important for fault-tolerant systems.

Even if the kernel option ipmi_si.trydefaults=0 is specified, ipmi_si discovers and claims one of the KCS interfaces on a Stratus server. The inability to now prevent the kernel from managing this device is a regression from previous kernels. The regression breaks a capability fault-tolerant vendors have relied upon.

To support both ACPI opregion access and the need to avoid activation of ipmi_si on some platforms, we've added two new kernel options, ipmi_si.tryacpi and ipmi_si.trydmi be added to prevent ipmi_si from initializing when these options are set to 0 on the kernel command line. With these options at the default value of 1, ipmi_si init proceeds according to the kernel default.

Tested-by Jim Paradis <[email protected]>

Signed-off-by Robert Evans <[email protected]>

Signed-off-by Jim Paradis <[email protected]>

Signed-off-by Tony Camuso <[email protected]>

---
  drivers/char/ipmi/ipmi_si_intf.c | 28 ++++++++++++++++++++++++----
  1 file changed, 24 insertions(+), 4 deletions(-)

drivers/char/ipmi/ipmi_si_intf.c +24 -4

index 20ab5b3..0a441cf 100644
@@ -1208,6 +1208,12 @@ static int smi_num; /* Used to sequence the SMIs */
  #define DEFAULT_REGSPACING	1
  #define DEFAULT_REGSIZE		1
 
+#ifdef CONFIG_ACPI
+static int           si_tryacpi = 1;
+#endif
+#ifdef CONFIG_DMI
+static int           si_trydmi = 1;
+#endif
  static bool          si_trydefaults = 1;
  static char          *si_type[SI_MAX_PARMS];
  #define MAX_SI_TYPE_STR 30

@@ -1238,6 +1244,16 @@ MODULE_PARM_DESC(hotmod, "Add and remove interfaces.  See"
  		 " Documentation/IPMI.txt in the kernel sources for the"
  		 " gory details.");
 
+#ifdef CONFIG_ACPI
+module_param_named(tryacpi, si_tryacpi, bool, 0);
+MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the"
+		 " default scan of the interfaces identified via ACPI");
+#endif
+#ifdef CONFIG_DMI
+module_param_named(trydmi, si_trydmi, bool, 0);
+MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the"
+		 " default scan of the interfaces identified via DMI");
+#endif
  module_param_named(trydefaults, si_trydefaults, bool, 0);
  MODULE_PARM_DESC(trydefaults, "Setting this to 'false' will disable the"
  		 " default scan of the KCS and SMIC interface at the standard"

@@ -3408,16 +3424,20 @@ static int init_ipmi_si(void)
  #endif
 
  #ifdef CONFIG_ACPI
-	pnp_register_driver(&ipmi_pnp_driver);
-	pnp_registered = 1;
+	if (si_tryacpi) {
+		pnp_register_driver(&ipmi_pnp_driver);
+		pnp_registered = 1;
+	}
  #endif
 
  #ifdef CONFIG_DMI
-	dmi_find_bmc();
+	if (si_trydmi)
+		dmi_find_bmc();
  #endif
 
  #ifdef CONFIG_ACPI
-	spmi_find_bmc();
+	if (si_tryacpi)
+		spmi_find_bmc();
  #endif
 
  	/* We prefer devices with interrupts, but in the case of a machine

Well, the built-in driver works on systems that have more than one interface and more than one BMC, and multiple IPMBs (and all of the other channel types for that matter, and the driver handles all the multiplexing and nasty addressing). There is, in fact, no arbitrary limit, and IBM tested this fairly extensively with some of their systems. I'm not sure why you would need a custom driver, and if there are some custom things that need to be done for your servers, I'd be happy to add that. I've worked with a number of other vendors to get changes like this in. And then ipmitool, freeipmi, openipmi, etc. will work with the device.

I don't have a big problem with this patch. I wonder why you would want to compile the standard driver into your kernel if you expected to load a module with a custom driver later, though. None of the distros I know of compile it in, it's always a module.

You can also dynamically remove the device from the driver using the hot add/remove capability. To remove it, you can do:
echo remove,cat /proc/ipmi/0/params
and it will disassociate that device (IPMI interface 0 in this case) from the driver. So you can iterate through all the devices in /proc/ipmi and remove them all at startup.

If none of the above options work for you, we can go ahead with this patch. Just wanted to let you know that current options exist, and see if you wanted to take a different direction.

-corey

Upstream commit 9e368fa0 added function ipmi_pnp_probe(), which calls try_smi_init() directly.

try_smi_init() allocates resources for IPMI driver. However try_smi_init() can be called again, and the allocated resources can be unexpectedly released when the same IPMI resource information is found on both ACPI namespace and SMBIOS table. ipmi_pnp_probe() should call add_smi() instead of try_smi_init()

For reference, see upstream commit ...
2407d77a1a013b88ee3b817f2b934e420e5376f5

Signed-off-by Tony Camuso <[email protected]>

---
  drivers/char/ipmi/ipmi_si_intf.c |    2 +-
  1 files changed, 1 insertions(+), 1 deletions(-)

drivers/char/ipmi/ipmi_si_intf.c +1 -1

index afb89be..20d13c6 100644
@@ -2223,7 +2223,7 @@ static int __devinit ipmi_pnp_probe(struct pnp_dev *dev,
      info->dev = &dev->dev;
      pnp_set_drvdata(dev, info);
 
-    return try_smi_init(info);
+    return add_smi(info);
 
  err_free:
      kfree(info);

The configuration change building ipmi_si into the kernel precludes

use of a custom driver that can utilize more than one KCS interface, multiple IPMBs, and more than one BMC. This capability is important

fault-tolerant systems.

Even if the kernel option ipmi_si.trydefaults=0 is specified, ipmi_si discovers and claims one of the KCS interfaces on a Stratus server. The inability to now prevent the kernel from managing this device is a regression from previous kernels. The regression breaks a capability fault-tolerant vendors have relied upon.

To support both ACPI opregion access and the need to avoid activation of ipmi_si on some platforms, we've added two new kernel options, ipmi_si.tryacpi and ipmi_si.trydmi be added to prevent ipmi_si from initializing when these options are set to 0 on the kernel command

With these options at the default value of 1, ipmi_si init proceeds according to the kernel default.

Tested-by Jim Paradis <[email protected]>

Signed-off-by Robert Evans <[email protected]>

Signed-off-by Jim Paradis <[email protected]>

Signed-off-by Tony Camuso <[email protected]>

drivers/char/ipmi/ipmi_si_intf.c +2 -0

  		 " Documentation/IPMI.txt in the kernel sources for the"
  		 " gory details.");
 
+#ifdef CONFIG_ACPI
+module_param_named(tryacpi, si_tryacpi, bool, 0);

drivers/char/ipmi/ipmi_si_intf.c +5 -3

@@ -3408,16 +3424,20 @@ static int init_ipmi_si(void)
  #endif
 
  #ifdef CONFIG_ACPI
-	pnp_register_driver(&ipmi_pnp_driver);
-	pnp_registered = 1;
+	if (si_tryacpi) {
+		pnp_register_driver(&ipmi_pnp_driver);
+		pnp_registered = 1;
+	}
  #endif
 
  #ifdef CONFIG_DMI
-	dmi_find_bmc();
+	if (si_trydmi)

Corey,

Thanks for the thoughtful reply. Below I respond in detail to these three points.

1) Why building a variant kernel with ipmi_si as a module is not feasible.

2) User mode access to IPMI on Stratus systems (e.g. ipmitool).

3) ipmi_si hot removal seems to not work as needed.

Stratus might be able to use the hot removal option instead of the proposed patch if hot removal can remove all interfaces from usage by ipmi_si. Our testing of this option was not successful as shown below.

- - -

1) Why building a variant kernel with ipmi_si as a module is not feasible:

Stratus sells servers based upon Red Hat Enterprise Linux (RHEL). In the next release of RHEL, ipmi_si will be built into the kernel so that access to ACPI opregion is available early in kernel startup. Stratus systems run the Red Hat kernel so that the system is certified and supported by Red Hat. For this reason using a custom kernel configured to build ipmi_si as a module is not an option.

2) User mode access to IPMI on Stratus systems:

Although Stratus provides a replacement for ipmi_si, we depend on ipmi_msghandler and ipmi_devintf. The device /dev/ipmi0 is present and this device is utilized by the user-mode system management software Stratus supplies.

Therefore other programs like ipmitool can send IPMI commands and get responses on Stratus systems.

3) Hot removal of the KCS interfaces discovered by ipmi_si seems to not do enough... One KCS cannot successfully be removed:

Based upon your suggestion, we tried to use hot removal. With RHEL 6.4 Beta (kernel-2.6.32-343.el6), Stratus attempted to hot remove the IPMI interfaces. This was booted with
"ipmi_si.trydefaults=0"
although we expect that kernel option to have no effect since a BMC is found before the defaults would be tried.

This is logged when ipmi_si initializes indicating that both BMCs were discovered:

ipmi message handler version 39.2
IPMI System Interface driver.
ipmi_si: Trying ACPI-specified kcs state machine at i/o address 0xca2, slave address 0x0, irq 0
ipmi: Found new BMC (man_id: 0x000077, prod_id: 0x05c6, dev_id: 0x41) IPMI kcs interface initialized
ipmi_si: Adding SMBIOS-specified kcs state machine
ipmi_si: Trying SMBIOS-specified kcs state machine at i/o address 0xda2, slave address 0x20, irq 0
ipmi: interfacing existing BMC (man_id: 0x000077, prod_id: 0x05c6,
dev_id: 0x41)
IPMI kcs interface initialized

Although there are two different BMCs, because it says
"interfacing existing BMC"
it appears that ipmi_si assumes they are the same BMC.

Also, I notice the slave address for the first KCS (port CA2) seems wrong. Maybe these findings are relevant to what happens next.

After ipmi_si has been initialized, a script runs to load ftmod, the module that contains the Stratus IPMI driver. This code was added to hot remove the interfaces discovered by ipmi_si before loading ftmod:

for i in $(cd /proc/ipmi; ls)
do

     dev="IPMI${i}"
     params="$(cat /proc/ipmi/${i}/params)"
     msg="Considering removal of dev: ${dev} ${params}"
     logger -p kern.info -t `basename ${0}` "${msg}"
     echo "${msg}" > /dev/console
     [ -n "${params}" ] &&
	echo "remove,`cat /proc/ipmi/${i}/params`" \
		> /sys/module/ipmi_si/parameters/hotmod

done

In the console log we can see this script run prior to loading the Stratus ftmod.ko and we also see that ftmod exposes a BMC:

Considering removal of dev: IPMI0 kcs,i/o,0xca2,rsp=1,rsi=1,rsh=0,irq=0,ipmb=0
Considering removal of dev: IPMI1 kcs,i/o,0xda2,rsp=1,rsi=1,rsh=0,irq=0,ipmb=32
ftmod: module license 'LGPL' taints kernel.
Disabling lock debugging due to kernel taint
FTMOD version lsb-ft-ftmod-9.0.4-209
ftmod: GLOBAL_SIZE=4194304
ftmod: global_cc_memory 0xffff880037400000
ipmi: Found new BMC (man_id: 0x000000, prod_id: 0x0000, dev_id: 0x00) ipmi device interface

The KCS at port DA2 is removed from use by ipmi_si. However, the other KCS is still in use by ipmi_si. Like ipmi_si, the Stratus IPMI driver uses ipmi_msghandler. With two interfaces sending commands to the same BMC, responses seem to be misdirected. The Stratus management software cannot successfully commnicate with that BMC and many errors like this are logged by ipmi_msghandler:

IPMI message handler: BMC returned incorrect response, expected netfn 3d cmd 75, got netfn 3d cmd 71
IPMI message handler: BMC returned incorrect response, expected netfn 3d cmd 71, got netfn 19 cmd 20
IPMI message handler: BMC returned incorrect response, expected netfn b cmd 40, got netfn 3d cmd 71
IPMI message handler: BMC returned incorrect response, expected netfn 3d cmd 71, got netfn d cmd 2

I tried a few variations on the remove string, but never got ipmi_si to stop using the KCS at port CA2.

Quoted 22 lines · Robert

Corey,

Thanks for the thoughtful reply. Below I respond in detail to these three points.

1) Why building a variant kernel with ipmi_si as a module is not feasible.

2) User mode access to IPMI on Stratus systems (e.g. ipmitool).

3) ipmi_si hot removal seems to not work as needed.

Stratus might be able to use the hot removal option instead of the proposed patch if hot removal can remove all interfaces from usage by ipmi_si. Our testing of this option was not successful as shown below.

- - -

1) Why building a variant kernel with ipmi_si as a module is not feasible:

Quoted 7 lines

Stratus sells servers based upon Red Hat Enterprise Linux (RHEL). In the next release of RHEL, ipmi_si will be built into the kernel so that access to ACPI opregion is available early in kernel startup. Stratus systems run the Red Hat kernel so that the system is certified and supported by Red Hat. For this reason using a custom kernel configured to build ipmi_si as a module is not an option.

Yes, the RHEL engineer explained this to me, and it makes sense now.

Quoted 10 lines

2) User mode access to IPMI on Stratus systems:

Although Stratus provides a replacement for ipmi_si, we depend on ipmi_msghandler and ipmi_devintf. The device /dev/ipmi0 is present and this device is utilized by the user-mode system management software Stratus supplies.

Quoted 2 lines

Therefore other programs like ipmitool can send IPMI commands and get responses on Stratus systems.

Ah, ok. That's good.

Quoted 19 lines

3) Hot removal of the KCS interfaces discovered by ipmi_si seems to not do enough... One KCS cannot successfully be removed:

Based upon your suggestion, we tried to use hot removal. With RHEL 6.4 Beta (kernel-2.6.32-343.el6), Stratus attempted to hot remove the IPMI interfaces. This was booted with
"ipmi_si.trydefaults=0"
although we expect that kernel option to have no effect since a BMC is found before the defaults would be tried.

This is logged when ipmi_si initializes indicating that both BMCs were discovered:

ipmi message handler version 39.2
IPMI System Interface driver.
ipmi_si: Trying ACPI-specified kcs state machine at i/o address

Quoted 2 lines

slave address 0x0, irq 0
ipmi: Found new BMC (man_id: 0x000077, prod_id: 0x05c6, dev_id:

Quoted 3 lines

IPMI kcs interface initialized
ipmi_si: Adding SMBIOS-specified kcs state machine
ipmi_si: Trying SMBIOS-specified kcs state machine at i/o address

Quoted 8 lines

slave address 0x20, irq 0
ipmi: interfacing existing BMC (man_id: 0x000077, prod_id: 0x05c6,
dev_id: 0x41)
IPMI kcs interface initialized

Although there are two different BMCs, because it says
"interfacing existing BMC"
it appears that ipmi_si assumes they are the same BMC.

That's happening in the message handler and it happens because the manufacturer, product, and device id all match. From the spec:

The Device ID is typically used in combination with the Product ID field such
that the Device IDs for different controllers are unique under a given Product
ID. A controller can optionally use the Device ID as an 'instance' identifier if
more than one controller of that kind is used in the system. (Section 20.1)

Different controllers in the same system are supposed to have different

device
IDs.

Quoted 3 lines

Also, I notice the slave address for the first KCS (port CA2) seems wrong. Maybe these findings are relevant to what happens next.

Probably not relevant. It's not correct because, for some bizarre reason, the slave address is not present in the ACPI information. The slave address is only used by the message handler for the IPMB return address on messages routed over IPMB.

It is odd that one interface is specified in ACPI and the other in DMI. You can specify all of them in both tables.

Quoted 20 lines

After ipmi_si has been initialized, a script runs to load ftmod, the module that contains the Stratus IPMI driver. This code was added to hot remove the interfaces discovered by ipmi_si before loading ftmod:

for i in $(cd /proc/ipmi; ls)
do

     dev="IPMI${i}"
     params="$(cat /proc/ipmi/${i}/params)"
     msg="Considering removal of dev: ${dev} ${params}"
     logger -p kern.info -t `basename ${0}` "${msg}"
     echo "${msg}" > /dev/console
     [ -n "${params}" ] &&
	echo "remove,`cat /proc/ipmi/${i}/params`" \
		> /sys/module/ipmi_si/parameters/hotmod

done

In the console log we can see this script run prior to loading the Stratus ftmod.ko and we also see that ftmod exposes a BMC:

Quoted 10 lines

Considering removal of dev: IPMI0 kcs,i/o,0xca2,rsp=1,rsi=1,rsh=0,irq=0,ipmb=0 Considering removal of dev: IPMI1 kcs,i/o,0xda2,rsp=1,rsi=1,rsh=0,irq=0,ipmb=32
ftmod: module license 'LGPL' taints kernel.
Disabling lock debugging due to kernel taint
FTMOD version lsb-ft-ftmod-9.0.4-209
ftmod: GLOBAL_SIZE=4194304
ftmod: global_cc_memory 0xffff880037400000
ipmi: Found new BMC (man_id: 0x000000, prod_id: 0x0000, dev_id:

Quoted 6 lines

ipmi device interface

The KCS at port DA2 is removed from use by ipmi_si. However, the other KCS is still in use by ipmi_si. Like ipmi_si, the Stratus IPMI driver uses ipmi_msghandler. With two interfaces sending commands to the same BMC, responses seem to be misdirected. The Stratus

Quoted 4 lines

software cannot successfully commnicate with that BMC and many errors like this are logged by ipmi_msghandler:

IPMI message handler: BMC returned incorrect response, expected netfn

Quoted 2 lines

cmd 75, got netfn 3d cmd 71
IPMI message handler: BMC returned incorrect response, expected netfn

Quoted 2 lines

cmd 71, got netfn 19 cmd 20
IPMI message handler: BMC returned incorrect response, expected netfn

Quoted 2 lines

cmd 40, got netfn 3d cmd 71
IPMI message handler: BMC returned incorrect response, expected netfn

Quoted 4 lines

cmd 71, got netfn d cmd 2

I tried a few variations on the remove string, but never got ipmi_si to stop using the KCS at port CA2.

When you remove it, does it disappear from /proc/ipmi? That directory should be empty after running your script.

The other strange thing is that, if the other driver is running, the request_region() call in your driver should fail.

Perhaps the first driver is leaving the device in a strange state that

confusing your driver? That doesn't seem possible. Or maybe there is something in the message handler that is getting messed up? There was a bug in the driver at one point that caused errors like that intermittently, but not all the time.

After sleeping on it a bit, though, I think the patch is a good idea,

I'll also add something for openfirmware and PCI. I was hoping to get you a quicker solution, though, than having to deal with a patch.

-corey

Quoted 31 lines · Corey Minyard

Quoted 29 lines · Robert

Corey,

Thanks for the thoughtful reply. Below I respond in detail to these three points.

1) Why building a variant kernel with ipmi_si as a module is not feasible.

2) User mode access to IPMI on Stratus systems (e.g. ipmitool).

3) ipmi_si hot removal seems to not work as needed.

Stratus might be able to use the hot removal option instead of the proposed patch if hot removal can remove all interfaces from usage by ipmi_si. Our testing of this option was not successful as shown below.

- - -

1) Why building a variant kernel with ipmi_si as a module is not feasible:

Stratus sells servers based upon Red Hat Enterprise Linux (RHEL). In the next release of RHEL, ipmi_si will be built into the kernel so that access to ACPI opregion is available early in kernel startup. Stratus systems run the Red Hat kernel so that the system is certified and supported by Red Hat. For this reason using a custom kernel configured to build ipmi_si as a module is not an option.

Quoted 1 line

Yes, the RHEL engineer explained this to me, and it makes sense now.

Quoted 28 lines

Quoted 5 lines

2) User mode access to IPMI on Stratus systems:

Quoted 7 lines

Although Stratus provides a replacement for ipmi_si, we depend on ipmi_msghandler and ipmi_devintf. The device /dev/ipmi0 is present and this device is utilized by the user-mode system management software Stratus supplies.

Therefore other programs like ipmitool can send IPMI commands and get responses on Stratus systems.

Ah, ok. That's good.

Quoted 13 lines

3) Hot removal of the KCS interfaces discovered by ipmi_si seems to not do enough... One KCS cannot successfully be removed:

Based upon your suggestion, we tried to use hot removal. With RHEL 6.4 Beta (kernel-2.6.32-343.el6), Stratus attempted to hot remove the IPMI interfaces. This was booted with
"ipmi_si.trydefaults=0"
although we expect that kernel option to have no effect since a BMC is found before the defaults would be tried.

Quoted 6 lines

Quoted 6 lines

This is logged when ipmi_si initializes indicating that both BMCs were discovered:

ipmi message handler version 39.2
IPMI System Interface driver.
ipmi_si: Trying ACPI-specified kcs state machine at i/o address

Quoted 2 lines

Quoted 2 lines

slave address 0x0, irq 0
ipmi: Found new BMC (man_id: 0x000077, prod_id: 0x05c6, dev_id:

Quoted 3 lines

Quoted 3 lines

IPMI kcs interface initialized
ipmi_si: Adding SMBIOS-specified kcs state machine
ipmi_si: Trying SMBIOS-specified kcs state machine at i/o address

Quoted 21 lines

Quoted 8 lines

slave address 0x20, irq 0
ipmi: interfacing existing BMC (man_id: 0x000077, prod_id: 0x05c6,
dev_id: 0x41)
IPMI kcs interface initialized

Although there are two different BMCs, because it says
"interfacing existing BMC"
it appears that ipmi_si assumes they are the same BMC.

That's happening in the message handler and it happens because the manufacturer, product, and device id all match. From the spec:

The Device ID is typically used in combination with the Product ID field such
that the Device IDs for different controllers are unique under a given Product
ID. A controller can optionally use the Device ID as an 'instance' identifier if
more than one controller of that kind is used in the system. (Section 20.1)

Quoted 1 line

Different controllers in the same system are supposed to have

Quoted 2 lines

device
IDs.

I have a made an inquiry to Stratus Hardware Engineering asking why our product is not compliant with the specification. I will pursue a

to future products to comply. However, Stratus has several generations of systems in the field for which this change will be very difficult.

Quoted 10 lines

Quoted 3 lines

Also, I notice the slave address for the first KCS (port CA2) seems wrong. Maybe these findings are relevant to what happens next.

Probably not relevant. It's not correct because, for some bizarre reason, the slave address is not present in the ACPI information. The slave address is only used by the message handler for the IPMB return address on messages routed over IPMB.

It is odd that one interface is specified in ACPI and the other in

Quoted 1 line

You can specify all of them in both tables.

The Stratus server is actually two complete servers that operate in lockstep to provide reliable operation regardless of any single failed component. One of the two I/O subsystems is active during BIOS POST. Only information about the active subsystem is placed in the SMBIOS data structure. Thus dmidecode shows this info for either port CA2 or DA2 depending upon which I/O CRU was active:

Handle 0x0048, DMI type 38, 18 bytes
IPMI Device Information
Interface Type: KCS (Keyboard Control Style) Specification Version: 2.0
I2C Slave Address: 0x10
NV Storage Device: Not Present
Base Address: 0x0000000000000DA2 (I/O) Register Spacing: Successive Byte Boundaries Interrupt Polarity: Active High Interrupt Trigger Mode: Edge

I believe the ACPI data provides information to locate both KCS

Therefore only one interface is found at first when ipmi_si calls dmi_find_bmc(). And the other interface is discovered by

or by ipmi_pnp_probe().

Quoted 3 lines

Quoted 3 lines

After ipmi_si has been initialized, a script runs to load ftmod, the module that contains the Stratus IPMI driver. This code was added

Quoted 1 line

Quoted 1 line

hot remove the interfaces discovered by ipmi_si before loading

Quoted 16 lines

Quoted 16 lines

for i in $(cd /proc/ipmi; ls)
do

     dev="IPMI${i}"
     params="$(cat /proc/ipmi/${i}/params)"
     msg="Considering removal of dev: ${dev} ${params}"
     logger -p kern.info -t `basename ${0}` "${msg}"
     echo "${msg}" > /dev/console
     [ -n "${params}" ] &&
	echo "remove,`cat /proc/ipmi/${i}/params`" \
		> /sys/module/ipmi_si/parameters/hotmod

done

In the console log we can see this script run prior to loading the Stratus ftmod.ko and we also see that ftmod exposes a BMC:

Quoted 10 lines

Quoted 10 lines

Considering removal of dev: IPMI0 kcs,i/o,0xca2,rsp=1,rsi=1,rsh=0,irq=0,ipmb=0 Considering removal of dev: IPMI1 kcs,i/o,0xda2,rsp=1,rsi=1,rsh=0,irq=0,ipmb=32
ftmod: module license 'LGPL' taints kernel.
Disabling lock debugging due to kernel taint
FTMOD version lsb-ft-ftmod-9.0.4-209
ftmod: GLOBAL_SIZE=4194304
ftmod: global_cc_memory 0xffff880037400000
ipmi: Found new BMC (man_id: 0x000000, prod_id: 0x0000, dev_id:

Quoted 4 lines

Quoted 4 lines

ipmi device interface

The KCS at port DA2 is removed from use by ipmi_si. However, the other KCS is still in use by ipmi_si. Like ipmi_si, the Stratus

Quoted 1 line

Quoted 1 line

driver uses ipmi_msghandler. With two interfaces sending commands

Quoted 1 line

Quoted 1 line

the same BMC, responses seem to be misdirected. The Stratus

Quoted 1 line

Quoted 1 line

software cannot successfully commnicate with that BMC and many

Quoted 3 lines

Quoted 3 lines

like this are logged by ipmi_msghandler:

IPMI message handler: BMC returned incorrect response, expected

Quoted 2 lines

Quoted 2 lines

cmd 75, got netfn 3d cmd 71
IPMI message handler: BMC returned incorrect response, expected

Quoted 2 lines

Quoted 2 lines

cmd 71, got netfn 19 cmd 20
IPMI message handler: BMC returned incorrect response, expected

Quoted 2 lines

Quoted 2 lines

cmd 40, got netfn 3d cmd 71
IPMI message handler: BMC returned incorrect response, expected

Quoted 7 lines

Quoted 4 lines

cmd 71, got netfn d cmd 2

I tried a few variations on the remove string, but never got ipmi_si to stop using the KCS at port CA2.

When you remove it, does it disappear from /proc/ipmi? That directory should be empty after running your script.

After my script runs, the kernel still has one device (0) with with the proc files from ipmi_si and from ipmi_msghandler. I see those

exist after my script runs, but before the Stratus driver gets loaded.

After it is loaded, the Stratus driver is using device (1). For that device, I only see the proc files exposed by ipmi_msghandler:

 # ls /proc/ipmi/?
 /proc/ipmi/0:
 ipmb  params  si_stats  stats  type  version

/proc/ipmi/1:
ipmb stats version

I still am experimenting with this as I am curious about why the hot- remove is not working.

Quoted 3 lines

The other strange thing is that, if the other driver is running, the request_region() call in your driver should fail.

The Stratus common low-level machine control code is shared by a few different operating systems. I do not have a list of all the I/O ports the common code accesses. So there is no request for a I/O port region when the Stratus common code starts. The linux- specific wrapper around common code simply does in or out instructions to access the requested ports.

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Perhaps the first driver is leaving the device in a strange state that

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confusing your driver? That doesn't seem possible. Or maybe there is something in the message handler that is getting messed up? There was a bug in the driver at one point that caused errors like that intermittently, but not all the time.

I think this is unlikely as the Stratus driver does retries and even can use a GPIO to reboot the BMC when communications fail.

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After sleeping on it a bit, though, I think the patch is a good idea,

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I'll also add something for openfirmware and PCI. I was hoping to get you a quicker solution, though, than having to deal with a patch.

-corey

I appreciate your help and would like the patch as it seems the best solution for existing systems. Thanks again for your assistance.

- Robert N. Evans