From 5cee4cf52bb3c6ec6bfdf5e71de93bf2f5a0f72b Mon Sep 17 00:00:00 2001
From: Sascha Wildner <saw@online.de>
Date: Sat, 7 Apr 2012 15:18:59 +0200
Subject: [PATCH] Document which drivers are using MSI and how it can be
 disabled.

---
 share/man/man4/ahci.4    | 8 +++++++-
 share/man/man4/arcmsr.4  | 8 +++++++-
 share/man/man4/bce.4     | 6 ++++--
 share/man/man4/em.4      | 6 ++++--
 share/man/man4/isp.4     | 8 +++++++-
 share/man/man4/jme.4     | 9 +++++++--
 share/man/man4/mfi.4     | 8 +++++++-
 share/man/man4/snd_hda.4 | 9 +++++++--
 8 files changed, 50 insertions(+), 12 deletions(-)

diff --git a/share/man/man4/ahci.4 b/share/man/man4/ahci.4
index 9f9aa60b6c..32a0c2fd99 100644
--- a/share/man/man4/ahci.4
+++ b/share/man/man4/ahci.4
@@ -14,7 +14,7 @@
 .\" TORTIOUS ACTION, ARISING OUT OF
 .\" PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd August 3, 2009
+.Dd April 7, 2012
 .Dt AHCI 4
 .Os
 .Sh NAME
@@ -91,6 +91,12 @@ some devices might not properly implement.
 hint.ahci.force150=1
 hint.ahci.nofeatures=1
 .Ed
+.Pp
+By default, the driver will use MSI if it is supported.
+This behavior can be turned off by setting the following tunable:
+.Bd -literal -offset indent
+hw.ahci.msi.enable=0
+.Ed
 .Sh SYSCTL VARIABLES
 Link power management can be set with the sysctl
 .Va hw.ahci%d.%d.link_pwr_mgmt
diff --git a/share/man/man4/arcmsr.4 b/share/man/man4/arcmsr.4
index 3c498eef0b..3711495fae 100644
--- a/share/man/man4/arcmsr.4
+++ b/share/man/man4/arcmsr.4
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD: src/share/man/man4/arcmsr.4,v 1.6 2008/03/28 23:25:58 brueffer Exp $
 .\"
-.Dd September 6, 2010
+.Dd April 7, 2012
 .Dt ARCMSR 4
 .Os
 .Sh NAME
@@ -65,6 +65,12 @@ A management interface is also present via the
 .Pa /dev/arcmsr?
 device node.
 Management tools for i386 and amd64 are available from Areca.
+.Sh LOADER TUNABLES
+.Bl -tag -width indent
+.It Va hw.arcmsr.msi.enable
+By default, the driver will use MSI if it is supported.
+This behavior can be turned off by setting this tunable to 0.
+.El
 .Sh HARDWARE
 The
 .Nm
diff --git a/share/man/man4/bce.4 b/share/man/man4/bce.4
index 61363ad60c..570edf6b98 100644
--- a/share/man/man4/bce.4
+++ b/share/man/man4/bce.4
@@ -27,9 +27,8 @@
 .\" THE POSSIBILITY OF SUCH DAMAGE.
 .\"
 .\" $FreeBSD: src/share/man/man4/bce.4,v 1.7 2007/02/09 18:26:13 brueffer Exp $
-.\" $DragonFly: src/share/man/man4/bce.4,v 1.5 2008/07/22 11:49:22 sephe Exp $
 .\"
-.Dd May 29, 2008
+.Dd April 7, 2012
 .Dt BCE 4
 .Os
 .Sh NAME
@@ -185,6 +184,9 @@ How often status block should be updated by the device
 during host interrupt processing,
 due to receiving packets.
 Default value is 18 (microseconds).
+.It Va hw.bce.msi.enable
+By default, the driver will use MSI if it is supported.
+This behavior can be turned off by setting this tunable to 0.
 .El
 .Sh HARDWARE
 The
diff --git a/share/man/man4/em.4 b/share/man/man4/em.4
index 2f99fb5757..1321499c26 100644
--- a/share/man/man4/em.4
+++ b/share/man/man4/em.4
@@ -30,9 +30,8 @@
 .\" * Other names and brands may be claimed as the property of others.
 .\"
 .\" $FreeBSD: src/share/man/man4/em.4,v 1.30 2008/10/06 21:55:53 simon Exp $
-.\" $DragonFly: src/share/man/man4/em.4,v 1.12 2008/07/11 10:38:50 thomas Exp $
 .\"
-.Dd February 27, 2009
+.Dd April 7, 2012
 .Dt EM 4
 .Os
 .Sh NAME
@@ -221,6 +220,9 @@ If
 is not used on the hardware and
 the major part of the transmitted data are bulk data,
 this value could safely be set to 1/2 of the number of transmit descriptors.
+.It Va hw.em.msi.enable
+By default, the driver will use MSI if it is supported.
+This behavior can be turned off by setting this tunable to 0.
 .El
 .Sh DIAGNOSTICS
 .Bl -diag
diff --git a/share/man/man4/isp.4 b/share/man/man4/isp.4
index 6ca513095a..93349e59ac 100644
--- a/share/man/man4/isp.4
+++ b/share/man/man4/isp.4
@@ -29,7 +29,7 @@
 .\"
 .\" $FreeBSD: src/share/man/man4/isp.4,v 1.29 2010/10/08 12:40:16 uqs Exp $
 .\"
-.Dd January 3, 2012
+.Dd April 7, 2012
 .Dt ISP 4
 .Os
 .Sh NAME
@@ -198,6 +198,12 @@ A hint value for a driver debug level (see the file
 .Pa /usr/src/sys/dev/isp/ispvar.h
 for the values.
 .El
+.Pp
+By default, the driver will use MSI if it is supported.
+This behavior can be turned off by setting the following tunable:
+.Bd -literal -offset indent
+hw.isp.msi.enable=0
+.Ed
 .Sh SYSCTL OPTIONS
 .Bl -tag -width indent
 .It Va dev.isp.N.loop_down_limit
diff --git a/share/man/man4/jme.4 b/share/man/man4/jme.4
index ca3bc29528..b2c0c0f8fd 100644
--- a/share/man/man4/jme.4
+++ b/share/man/man4/jme.4
@@ -23,9 +23,8 @@
 .\" SUCH DAMAGE.
 .\"
 .\" $FreeBSD: src/share/man/man4/jme.4,v 1.1 2008/05/27 01:59:17 yongari Exp $
-.\" $DragonFly: src/share/man/man4/jme.4,v 1.3 2008/07/27 19:38:58 swildner Exp $
 .\"
-.Dd July 26, 2008
+.Dd April 7, 2012
 .Dt JME 4
 .Os
 .Sh NAME
@@ -101,6 +100,12 @@ The
 .Nm
 driver supports
 .Xr polling 4 .
+.Ss Loader Tunables
+By default, the driver will use MSI if it is supported.
+This behavior can be turned off by setting the following tunable:
+.Bd -literal -offset indent
+hw.jme.msi.enable=0
+.Ed
 .Ss MIB Variables
 A number of per-interface variables are implemented in the
 .Va hw.jme Ns Em X
diff --git a/share/man/man4/mfi.4 b/share/man/man4/mfi.4
index 54979a8865..6d0e796345 100644
--- a/share/man/man4/mfi.4
+++ b/share/man/man4/mfi.4
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD: src/share/man/man4/mfi.4,v 1.13 2010/05/12 17:12:38 brueffer Exp $
 .\"
-.Dd March 24, 2012
+.Dd April 7, 2012
 .Dt MFI 4
 .Os
 .Sh NAME
@@ -86,6 +86,12 @@ If the sysctl
 .Va dev.mfi.%d.delete_busy_volumes
 is set to 1,
 then the driver will allow mounted volumes to be removed.
+.Sh LOADER TUNABLES
+.Bl -tag -width indent
+.It Va hw.mfi.msi.enable
+By default, the driver will use MSI if it is supported.
+This behavior can be turned off by setting this tunable to 0.
+.El
 .Sh HARDWARE
 The
 .Nm
diff --git a/share/man/man4/snd_hda.4 b/share/man/man4/snd_hda.4
index 5f0970d643..6ce4e602b6 100644
--- a/share/man/man4/snd_hda.4
+++ b/share/man/man4/snd_hda.4
@@ -23,9 +23,8 @@
 .\" SUCH DAMAGE.
 .\"
 .\" $FreeBSD: src/share/man/man4/snd_hda.4,v 1.10.2.1 2007/05/15 18:40:22 joel Exp $
-.\" $DragonFly: src/share/man/man4/snd_hda.4,v 1.2 2007/06/16 17:44:33 hasso Exp $
 .\"
-.Dd May 5, 2007
+.Dd April 7, 2012
 .Dt SND_HDA 4
 .Os
 .Sh NAME
@@ -89,6 +88,12 @@ Polling is disabled by default.
 Do not enable it unless you are facing weird interrupt problems or if the
 device cannot generate interrupts at all.
 .El
+.Sh LOADER TUNABLES
+.Bl -tag -width indent
+.It Va hw.snd.hdac.msi.enable
+By default, the driver will use MSI if it is supported.
+This behavior can be turned off by setting this tunable to 0.
+.El
 .Sh HARDWARE
 The
 .Nm
-- 
2.41.0