diff --git a/share/man/man4/rtw88.4 b/share/man/man4/rtw88.4
index b34fbf96c5df..0ace002e4bde 100644
--- a/share/man/man4/rtw88.4
+++ b/share/man/man4/rtw88.4
@@ -1,95 +1,111 @@
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 .\"
 .\" $FreeBSD$
 .\"
-.Dd March 31, 2022
+.Dd May 5, 2022
 .Dt rtw88 4
 .Os
 .Sh NAME
 .Nm rtw88
 .Nd Realtek IEEE 802.11n/ac wireless network driver
 .Sh SYNOPSIS
 The driver will auto-load without any user interaction using
 .Xr devmatch 8
 if enabled in
 .Xr rc.conf 5 .
 .Pp
 Only if auto-loading is explicitly disabled, place the following
 lines in
 .Xr rc.conf 5
 to manually load the driver as a module at boot time:
 .Bd -literal -offset indent
 kld_list="${kld_list} if_rtw88"
 .Ed
 .Pp
 The driver should automatically load any
 .Xr rtw88fw 4
 firmware needed for the particular chipset.
 .Pp
 It is discouraged to load the driver from
 .Xr loader 8 .
 .Sh DESCRIPTION
 The
 .Nm
 driver is derived from Realtek's Linux rtw88 driver and provides support for
 the following chipsets:
 .Pp
 .Bl -tag -width Ds -offset indent -compact
 .It Realtek 802.11n  wireless 8723de (RTL8723DE)
 .It Realtek 802.11ac wireless 8821ce (RTL8821CE)
 .It Realtek 802.11ac wireless 8822be (RTL8822BE)
 .It Realtek 802.11ac wireless 8822ce (RTL8822CE)
 .El
 .Pp
 The driver uses the
 .\" No LinuxKPI man pages so no .Xr here.
 .Em linuxkpi_wlan
 and
 .Em linuxkpi
 compat framework to bridge between the Linux and
 native FreeBSD driver code as well as to the native
 .Xr net80211 4
 wireless stack.
 .Pp
 While
 .Nm
 supports all 802.11 a/b/g/n and ac
 the compatibility code currently only supports 802.11 a/b/g modes.
 Support for 802.11 n/ac is to come.
+.Sh LOADER TUNABLES
+.Bl -tag -width indent
+.It Va compat.linuxkpi.skb.mem_limit
+If you are running a 64bit system with more than 4GB of main mmeory
+you need to set this tunable to
+.Sy 1
+in
+.Xr loader.conf 5
+and reboot once to make it effective.
+This tunable will work around a problem with DMA and limit allocations
+for network buffer memory to the lower 32bit of physical memory and
+make the driver work.
+.El
 .Sh BUGS
 Certainly.
 .Pp
 Does not seem to work (reliably) on machines with more than 4GB of
 main memory.
+See in the
+.Sx LOADER TUNABLES
+section above.
 .Sh SEE ALSO
 .Xr rtw88fw 4 ,
 .Xr wlan 4 ,
 .Xr ifconfig 8 ,
 .Xr wpa_supplicant 8
 .Sh HISTORY
 The
 .Nm
 driver first appeared in
 .Fx 14.0 .