.\"-
.\" Copyright (c) 2022 Bjoern A. Zeeb
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd June 12, 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_pci"
.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 .