freebsd-skq/share/man/man4/mps.4
Kenneth D. Merry 1476ba4087 Turn on serialization of task management commands going down to the
controller, but make it optional.

After a problem report from Andrew Boyer, it looks like the LSI
chip may have issues (the watchdog timer fired) if too many aborts
are sent down to the chip at the same time.  We know that task
management commands are serialized, and although the manual doesn't
say it, it may be a good idea to just send one at a time.

But, since I'm not certain that this is necessary, add a tunable
and sysctl variable (hw.mps.%d.allow_multiple_tm_cmds) to control
the driver's behavior.

mps.c:		Add support for the sysctl and tunable, and add a
		comment about the possible return values to
		mps_map_command().

mps_sas.c:	Run all task management commands through two new
		routines, mpssas_issue_tm_request() and
		mpssas_complete_tm_request().

		This allows us to optionally serialize task
		management commands.  Also, change things so that
		the response to a task management command always
		comes back through the callback.  (Before it could
		come via the callback or the return value.)

mpsvar.h:	Add softc variables for the list of active task
		management commands, the number of active commands,
		and whether we should allow multiple active task
		management commands.  Add an active command flag.

mps.4:		Describe the new sysctl/loader tunable variable.

Sponsored by:	Spectra Logic Corporation
2010-10-07 21:56:10 +00:00

174 lines
4.3 KiB
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.\" mps driver man page.
.\"
.\" Author: Ken Merry <ken@FreeBSD.org>
.\"
.\" $Id: //depot/SpectraBSD/head/share/man/man4/mps.4#4 $
.\" $FreeBSD$
.\"
.Dd September 13, 2010
.Dt MPS 4
.Os
.Sh NAME
.Nm mps
.Nd LSI Fusion-MPT 2 Serial Attached SCSI driver
.Sh SYNOPSIS
To compile this driver into your kernel,
place the following lines in your kernel configuration file:
.Bd -ragged -offset indent
.Cd "device scbus"
.Cd "device mps"
.Ed
.Pp
Or, to load the driver as a module at boot, place the following line in
.Xr loader.conf 5 :
.Bd -literal -offset indent
mps_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
driver provides support for LSI Logic Fusion-MPT 2
.Tn SAS
controllers.
.Sh HARDWARE
The following controllers are supported by the
.Nm
driver
.Pp
.Bl -bullet -compact
.It
LSI Logic SAS2004 (4 Port
.Tn SAS )
.It
LSI Logic SAS2008 (8 Port
.Tn SAS )
.It
LSI Logic SAS2108 (8 Port
.Tn SAS )
.It
LSI Logic SAS2116 (16 Port
.Tn SAS )
.It
LSI Logic SAS2208 (8 Port
.Tn SAS )
.El
.Sh CONFIGURATION
To disable MSI interrupts for all
.Nm
driver instances, set the following tunable value in
.Xr loader.conf 5 :
.Bd -literal -offset indent
hw.mps.disable_msi=1
.Ed
.Pp
To disable MSI-X interrupts for all
.Nm
driver instances, set the following tunable value in
.Xr loader.conf 5 :
.Bd -literal -offset indent
hw.mps.disable_msix=1
.Ed
.Pp
To allow the driver to send multiple task management commands (like abort,
LUN reset, etc.), set the following variable:
.Bd -literal -offset indent
hw.mps.X.allow_multiple_tm_cmds=1
.Ed
.Pp
via
.Xr loader.conf 5
or
.Xr sysctl 8 ,
where X is the adapter number.
By default the driver only sends one task management command at a time, to
avoid causing a potential controller lock-up.
.Sh DEBUGGING
To enable debugging prints from the
.Nm
driver, set the
.Bd -literal -offset indent
hw.mps.X.debug_level
.Ed
.Pp
variable, where X is the adapter number, either in
.Xr loader.conf 5
or via
.Xr sysctl 8 .
The following bits have the described effects:
.Bl -tag -offset indent
.It 0x01
Enable informational prints.
.It 0x02
Enable tracing prints.
.It 0x04
Enable prints for driver faults.
.It 0x08
Enable prints for controller events.
.El
.Sh SEE ALSO
.Xr cd 4 ,
.Xr ch 4 ,
.Xr da 4 ,
.Xr mpt 4 ,
.Xr pci 4 ,
.Xr sa 4 ,
.Xr scsi 4 ,
.Xr targ 4
.Sh BUGS
This driver is still in development, it has only been tested on the amd64
architecture and has some known shortcomings:
.Bl -bullet -compact
.It
No IR (Integrated RAID) support.
.It
No userland utility support (e.g.
.Xr mptutil 8).
.It
Sometimes the driver gets into a state where devices arrive and depart multiple
times, without user intervention.
.It
The error recovery code isn't complete.
.El
.Sh HISTORY
The
.Nm
driver first appeared in
.Fx 9.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was originally written by
.An Scott Long Aq scottl@FreeBSD.org .
This man page was written by
.An Ken Merry Aq ken@FreeBSD.org .