mpt.4: Warn about unexpected behaviour on older controllers

Older controllers have errata which causes the disk controller to wrap
data to other LBAs, causing data to be overwritten. [1]

While here, fix a small typo.

1: https://www.broadcom.com/support/knowledgebase/1211161496563/3-terabyte-3tb-capacity-drives-on-lsi-megaraid-and-3ware-control

PR: 220343
Submitted by:	Sebastian Oswald <sebastian at rostwald.de>
Reviewed by:	0mp
Event:		January 2021 Bugathon
Differential Revision:	<https://reviews.freebsd.org/D28201

1 files changed, 10 insertions, 2 deletions

diff --git a/share/man/man4/mpt.4 b/share/man/man4/mpt.4
index b3a29f633952..4f243eb1823c 100644
--- a/share/man/man4/mpt.4
+++ b/share/man/man4/mpt.4
@@ -35,7 +35,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd July 23, 2011
+.Dd January 16, 2021
 .Dt MPT 4
 .Os
 .Sh NAME
@@ -119,7 +119,7 @@ driver can be found onboard on many systems including:
 .Pp
 .Bl -bullet -compact
 .It
-Dell PowerEdge 1750 thru 2850
+Dell PowerEdge 1750 through 2850
 .It
 IBM eServer xSeries 335
 .El
@@ -149,6 +149,14 @@ This driver also supports target mode for Fibre Channel cards.
 This support may be enabled by setting the desired role of the core via
 the LSI Logic firmware utility that establishes what roles the card
 can take on - no separate compilation is required.
+.Sh WARNINGS
+Most controllers supported by the
+.Nm
+driver suffer from limitations on supported disk size (mostly <2TB).
+While most controllers will truncate usable disk size, others might
+behave unexpetedly and can cause severe data loss.
+Refer to the datasheet of the chipset and firmware version for information
+about supported disk size and limitations.
 .Sh SEE ALSO
 .Xr cd 4 ,
 .Xr ch 4 ,