Re: 15.0-RELEASE boot panic when if_iwm_load="YES"

On Sun, 30 Nov 2025 at 10:27, Karlo Miličević <karlo98.m@gmail.com> wrote:
>
> fwget said everything is up to date.
> This is what I get from pciconf:
> iwm0@pci0:2:0:0: class=0x028000 rev=0x83 hdr=0x00 vendor=0x8086
> device=0x08b3 subvendor=0x8086 subdevice=0x8070
>     vendor     = 'Intel Corporation'
>     device     = 'Wireless 3160'
>     class      = network
>
> It seems that the step of loading the driver at boot-time is
> unnecessary as it was already loaded and handling the device.
> I just needed this in rc.conf and wpa_supplicant.conf configuration:
> wlans_iwm0="wlan0"
> ifconfig_wlan0="WPA DHCP"
>
> It's a bit odd that every resource I find on the internet says to load
> it using the parameter in /boot/loader.conf when it's loaded by
> default.
> Also, the fact that it crashes when loaded like that.
> I remember I used to have nvidia driver hang/crash the system when
> loaded in loader.conf but it worked fine when loaded later.

As I said in my previous reply, firmware loading behaviours changed
between 14 and 15.
About the only NIC that hasn't had this happen is rtwn because the
firmware is super small
in comparison to everything else now (like, the firmware set for
current gen wifi/gpu
devices is > 200mbytes!) and it's good to have /something/ easy to
acquire that works
out of the box.



-adrian

>
> Thank you for the help, Dave!
>
> On Sun, Nov 30, 2025 at 1:18 PM Dave Cottlehuber <dch@skunkwerks.at> wrote:
> >
> > On Sat, 29 Nov 2025, at 16:00, Karlo Miličević wrote:
> > > I know 15.0 is not released yet but the image is up and I wanted to try
> > > it out on real hardware.
> > >
> > > After I put if_iwm_load="YES" in /boot/loader.conf it fails to boot.
> > > After saying it's loading loader.conf and briefly flashing FreeBSD logo
> > > I get a panic:
> > >
> > > panic: page fault
> > > cpuid = 0
> > > time = 1
> > > KDB: stack backtrace:
> > > #0 0xffffffff80bbe1ed at kdb_backtrace+0x5d
> > > #1 0xffffffff80b71576 at vpanic+0x136
> > > #2 0xffffffff80b71433 at panic+0x43
> > > #3 0xffffffff81079f69 at trap_pfault+0x3c9
> > > #4 0xffffffff8104ff18 at calltrap+0x8
> > > #5 0xffffffff80c4f974 at namei+0xe4
> > > #6 0xffffffff80c768b2 at vn_open_cred+0x5b2
> > > #7 0xffffffff80bb9ef4 at loadimage+0x274
> > > #8 0xffffffff80bd4de2 at taskqueue_run_locked+0x182
> > > #9 0xffffffff80bd5fb2 at taskqueue_thread_loop+0xc2
> > > #10 0xffffffff80b2786b at fork_exit+0x7b
> > > #11 0xffffffff81050f3e at fork_trampoline+0xe
> > > Uptime: 1s
> > > Automatic reboot in 15 seconds - press a key on the console to abort
> > >
> > > Am I doing something wrong?
> > > IIRC this worked on 14.3 on the same hardware.
> >
> > Hi Karlo
> >
> > I can't speak for the panic, but these other tips may help.
> >
> > Make sure you've got the relevant firmware - boot with iw_iwm disabled
> > (see below if devmatch attaches it automatically), and run `fwget`,
> > it should do the right thing even if the driver isn't loaded:
> >
> > # fwget
> > Needed firmware packages: 'wifi-firmware-mt76-kmod-mt792x ...
> > The most recent versions of packages are already installed
> >
> > The 15.0-RELEASE tag is already in sources, and signed, so there's
> > nothing release-specific we can do at this stage.
> >
> > You can try using the /latest/ FreeBSD ports tree (or via packages)
> > and make sure your intel firmware bundle is updated.
> >
> > I don't know what hardware you have, but if it's supported by
> > https://man.freebsd.org/iwlwifi then you can try that as an alternative,
> > it's seen a lot of development during the last few months.
> >
> > It's probably more convenient to late-load via rc.conf:
> >
> > devmatch_blocklist="if_iwmn"
> > kld_list="${kld_list} if_iwlwifi"
> >
> > This prevents the iwm driver being attached, and prefers the newer one
> > instead.
> >
> > There is also https://man.freebsd.org/if_iwx with overlapping hardware
> > support.
> >
> > In either case, thanks for testing, and consider logging a PR after
> > checking https://wiki.freebsd.org/WiFi/Iwlwifi#testing & seeing
> > if your issue is already reported in the meta-bug at https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=273620
> >
> > There is a freebsd-wireless@freebsd.org list too.
> >
> > I believe both 16-CURRENT and 15-STABLE have some new bits too already,
> > so that may be worth a try as a final resort.
> >
> > A+
> > Dave
>