The iwn(4) firmware forgets most of its channel state after an RXON
command. This means that any beacons its seen on passive 5GHz channels
are forgotten upon an association/authorisation request.
This unfortuantely means that 5GHz association almost always fails -
the assoc and/or auth frames are dropped with a status of "passive
channel, haven't seen a beacon yet." (0x90.)
So:
* add an xmit queue, global, to buffer frames
* modify the xmit path to use the mbuf tag from net80211
to specify raw frame details
* buffer xmit frames from both raw and non-raw paths
* if a beacon is seen in the RX path, schedule a taskqueue to
send said frames and un-buffer things.
* flush frames during state change back to INIT, or NIC
down/up/detach.
This isn't the final shape I'd like this to be in but it certainly
is better than 5GHz "not working at all".
Tested:
* Intel 5100, STA mode (before spilling coffee)
* Intel 5300, STA mode (after spilling coffee)
Story:
* This has been bugging me at work for months, which I just
worked around by throwing an ath(4) into my Lenovo T400 cardbus
slot.
* Our ops director discovered indeed FreeBSD runs well on the
Lenovo T420p, except for that pesky 5GHz thing. So now developers
also can have a T420p running FreeBSD to do work with.
Their #1 feedback to me - "boy it'd be nice if 5GHz wifi worked."
* .. then, I was at NANOG but stuck with 5GHz only wifi and no ath(4)
NIC to put in a laptop - and I snapped.
Thus, the reason this is actually work related.
MFC after: 2 weeks
Sponsored by: Norse Corp, Inc.
There was a inconsistency which led to enable passthrough commands
being interpreted as actual touchpad commands.
Submitted by: Jan Kokemüller <jan.kokemueller at gmail.com>
MFC after: 1 week
ct_rxid value on CTIO completion. Try to workaround that using tag_id
from the CCB, pointed by still valid ct_syshandle.
I don't know whether this is valid fix or dirty hack, but considering that
alternative is indefinitely stuck command -- it worth trying.
MFC after: 1 week
In bxe_set_mc_list(): added missing BXE_MCAST_UNLOCK()
In __ecore_vlan_mac_h_exec_pending(): need to check for ECORE_PENDING
Submitted by:gary.zambrano@qlogic.com
o rev. 1.10: Nuke trailing whitespace.
o rev. 1.15: Fix typo in comment.
o rev. 1.16: Add the following registers from IEEE 802.3-2009 Clause 22:
- PSE control register (0x0b)
- PSE status register (0x0c)
- MMD access control register (0x0d)
- MMD access address data register (0x0e)
o rev. 1.17 (comments only): The bit location of link ability is different
between 1000Base-X and others (see Annex 28B.2 and 28D).
o rev. 1.18: Nuke dupe word.
Obtained from: NetBSD
MFC after: 1 week
Sponsored by: genua mbh
This change re-organizes code a little bit to extract common pieces
of ttm_alloc_new_pages() and ttm_get_pages() into dedicated functions.
Also, for requests without address restrictions regular vm_page_alloc()
is used.
Lastly, when vm_page_alloc_contig() fails we call VM_WAIT before calling
vm_pageout_grow_cache() to ensure that there is enough free pages at all.
Reviewed by: kib
MFC after: 15 days
If the pathname is absolute or dirfd is AT_FDCWD we can
handle it exactly like open(2).
Otherwise we output an A record to indicate that the path of
an open directory needs to be used (earlier in the trace).
Differential Revision: D2810
Reviewed by: jhb
MFC after: a bit
vtnet interfaces are always in promiscuous mode (at least if the
VIRTIO_NET_F_CTRL_RX feature is not negotiated with the host). if_promisc() on
a vtnet interface returned ENOTSUP although it has IFF_PROMISC set. This
confused the bridge code. Instead we now accept all enable/disable promiscuous
commands (and always keep IFF_PROMISC set).
There are also two issues with the if_bridge error handling.
If if_promisc() fails it uses bridge_delete_member() to clean up. This tries to
disable promiscuous mode on the interface. That runs into an assert, because
promiscuous mode was never set in the first place. (That's the panic reported in
PR 200210.)
We can only unset promiscuous mode if the interface actually is promiscuous.
This goes against the reference counting done by if_promisc(), but only the
first/last if_promic() calls can actually fail, so this is safe.
A second issue is a double free of bif. It's already freed by
bridge_delete_member().
PR: 200210
Differential Revision: https://reviews.freebsd.org/D2804
Reviewed by: philip (mentor)
Add a check for NULL before strcmp on smbios information incase it is not populated
Differential Revision: https://reviews.freebsd.org/D2750
Reviewed by: ngie, jhb
Approved by: rpaulo
Sponsored by: ScaleEngine Inc.
bxe_ioctl() completes all functions within its context as opposed to a taskqueue earlier.
bxe_handle_rx_mode_tq() no longer required. bxe_set_rx_mode() handles the functionality within its context
Submitted by:gary.zambrano@qlogic.com
MFC after:5 days
which is default. It was broken in r281441.
It appears that set_trackpoint_parameters() call on resume disables the
mouse. So, we need not call it on resume if hw.psm.trackpoint_support=0.
The problem is that the probe functions are used both for probing and
for reiniting on resume. And the absense of the softc parameter is used
as a mark to distinguish reinit and probe, which is quite ugly. At the
same time the softc parameter is needed to call set_trackpoint_parameters().
o Change the arguments of probefunc_t to always supply the softc, and
use additional enum argument to tell probing from initing.
o Don't call set_trackpoint_parameters() from global doinitialize(),
instead call it from the enable_trackpoint() only.
o In enable_synaptics() call enable_trackpoint() in both probe and
reinit cases.
Together with: Jan Kokemüller <jan.kokemueller gmail.com>
Work based on Cavium Thunder PCIe driver by Semihalf.
Reviewed by: andrew, jhb
Sponsored by: HEIF5
Differential Revision: https://reviews.freebsd.org/D2386
PCI infrastructure instantiates a non-existent resource.
This has BARs suddenly show up with pciconf(8) under
VMware as well. Now that we read the BAR ourselves, ask
for the correct resource type.
The FreeBSD extension adds a new request type, called blkif_segment_block
which has a size of 112bytes for both i386 and amd64. This is fine on
amd64, since requests have a size of 112B there also. But this is not true
for i386, where requests have a size of 108B. So on i386 we basically
overrun the ring slot when queuing a request of type blkif_segment_block_t,
which is very bad.
Remove this extension (including a cleanup of the public blkif.h header
file) from blkfront and blkback.
Sponsored by: Citrix Systems R&D
Tested-by: cperciva
drivers, one for fdt, one for acpi. It then uses this to decide if it will
use fdt or acpi.
The GICv2 (interrupt controller) and Generic Timer drivers have been
updated to handle both cases.
As this is early code we still need FDT to find the kernel console, and
some parts are still missing, including PCI support.
Differential Revision: https://reviews.freebsd.org/D2463
Reviewed by: jhb, jkim, emaste
Obtained from: ABT Systems Ltd
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
Use the same scheme implemented to manage credentials.
Code needing to look at process's credentials (as opposed to thred's) is
provided with *_proc variants of relevant functions.
Places which possibly had to take the proc lock anyway still use the proc
pointer to access limits.
gracefully fail if the /dev/megaraid_sas_ioctl_node symlink already exists.
This can happen if mfi(4) and mrsas(4) are both attached to cards and
providing Linux emulation support. Let the first one win. An equivalent
change needs to be done to mrsas(4). Extra credit would be to pass the
Linux emulation call to the other driver when appropriate. This will
probably be a rare case and the user can manually change where the symlink
points to.
MFC after: 3 days
(easily) without having to go to other drivers to change the
magical return values. This wouldn't be so bad if there were
proper defines for these constants.
In particular dev/acpica/acpi_pcib_pci.c returns -1000 as the
probe priority and it's expected that this driver gets to
attach over the common PCI bus drivers.
Without creating a LAW entry, any access to the NAND hangs the CPU.
The original intent was to add a quirk to map all of the RouterBoard's LBC
address space in one shot, which would fix it for both NAND and the CF, and
that's probably still in the cards. However, for now, this makes NAND usable
without a separate hack.
Things left before the RouterBoard can run standalone:
* Add partitions to the NAND (not specified by the FDT, which we currently
require).
* Create a YAFFS partition for the kernel. The Mikrotik boot loader requires a
4MB partition at the beginning of NAND, with a file called 'kernel' in the
root.
Create a special resource (= device special file) for management
of tags and maps, as well as for mapping memory into the address
space. DMA resources are managed using the PROTO_IOC_BUSDMA ioctl.
Part 1 implements tag creation, derivation and destruction.
BUS_PROBE_HOOVER is. Drivers like proto(4), when compiled into the
kernel or preloaded, will render your system useless by virtue of
attaching to your PCI busses.
Return BUS_PROBE_GENERIC instead. It's just the next priority up
from BUS_PROBE_HOOVER. No other meaning has been give to its use.
While BUS_PROBE_DEFAULT seems like a better candidate, it's hard
not to think that there must be some reason why these drivers
return -10000 in the first place.
Differential Revision: D2705
code update, with supporting changes in the CORE. Changes for the extended
media types, VF driver has virtual channel protocol changes, and some
register use corrections. This software change should be coordinated with
Firmware updates to your hardware, contact your support channels for that.
MFC after: 1 week
logic is now placed in the mmap hook implementation rather than requiring
it to be placed in sys/vm/vm_mmap.c. This hook allows new file types to
support mmap() as well as potentially allowing mmap() for existing file
types that do not currently support any mapping.
The vm_mmap() function is now split up into two functions. A new
vm_mmap_object() function handles the "back half" of vm_mmap() and accepts
a referenced VM object to map rather than a (handle, handle_type) tuple.
vm_mmap() is now reduced to converting a (handle, handle_type) tuple to a
a VM object and then calling vm_mmap_object() to handle the actual mapping.
The vm_mmap() function remains for use by other parts of the kernel
(e.g. device drivers and exec) but now only supports mapping vnodes,
character devices, and anonymous memory.
The mmap() system call invokes vm_mmap_object() directly with a NULL object
for anonymous mappings. For mappings using a file descriptor, the
descriptors fo_mmap() hook is invoked instead. The fo_mmap() hook is
responsible for performing type-specific checks and adjustments to
arguments as well as possibly modifying mapping parameters such as flags
or the object offset. The fo_mmap() hook routines then call
vm_mmap_object() to handle the actual mapping.
The fo_mmap() hook is optional. If it is not set, then fo_mmap() will
fail with ENODEV. A fo_mmap() hook is implemented for regular files,
character devices, and shared memory objects (created via shm_open()).
While here, consistently use the VM_PROT_* constants for the vm_prot_t
type for the 'prot' variable passed to vm_mmap() and vm_mmap_object()
as well as the vm_mmap_vnode() and vm_mmap_cdev() helper routines.
Previously some places were using the mmap()-specific PROT_* constants
instead. While this happens to work because PROT_xx == VM_PROT_xx,
using VM_PROT_* is more correct.
Differential Revision: https://reviews.freebsd.org/D2658
Reviewed by: alc (glanced over), kib
MFC after: 1 month
Sponsored by: Chelsio
stability.
I'll re-enable it once the scan overhaul is done - the NIC itself
can do bgscan, but not how we're doing it.
MFC after: 2 weeks
Sponsored by: Norse Corp, Inc.
up to 2 rx/tx queues for the 82574.
Program the 82574 to enable 5 msix vectors, assign 1 to each rx queue,
1 to each tx queue and 1 to the link handler.
Inspired by DragonFlyBSD, enable some RSS logic for handling tx queue
handling/processing.
Move multiqueue handler functions so that they line up better in a diff
review to if_igb.c
Always enqueue tx work to be done in em_mq_start, if unable to acquire
the TX lock, then this will be processed in the background later by the
taskqueue. Remove mbuf argument from em_start_mq_locked() as the work
is always enqueued. (stolen from igb)
Setup TARC, TXDCTL and RXDCTL registers for better performance and stability
in multiqueue and singlequeue implementations. Handle Intel errata 3 and
generic multiqueue behavior with the initialization of TARC(0) and TARC(1)
Bind interrupt threads to cpus in order. (stolen from igb)
Add 2 new DDB functions, one to display the queue(s) and their settings and
one to reset the adapter. Primarily used for debugging.
In the multiqueue configuration, bump RXD and TXD ring size to max for the
adapter (4096). Setup an RDTR of 64 and an RADV of 128 in multiqueue configuration
to cut down on the number of interrupts. RADV was arbitrarily set to 2x RDTR
and can be adjusted as needed.
Cleanup the display in top a bit to make it clearer where the taskqueue threads
are running and what they should be doing.
Ensure that both queues are processed by em_local_timer() by writing them both
to the IMS register to generate soft interrupts.
Ensure that an soft interrupt is generated when em_msix_link() is run so that
any races between assertion of the link/status interrupt and a rx/tx interrupt
are handled.
Document existing tuneables: hw.em.eee_setting, hw.em.msix, hw.em.smart_pwr_down, hw.em.sbp
Document use of hw.em.num_queues and the new kernel option EM_MULTIQUEUE
Thanks to Intel for their continued support of FreeBSD.
Reviewed by: erj jfv hiren gnn wblock
Obtained from: Intel Corporation
MFC after: 2 weeks
Relnotes: Yes
Sponsored by: Limelight Networks
Differential Revision: https://reviews.freebsd.org/D1994
Previously the OACTIVE flag was being set when the tx descriptors are fully
allocated but it wasn't unset anywhere.
As soon as a packet is transmitted, unset the OACTIVE flag and call start
routine to push any pending packets from the tx queue.
This closes another race where a full tx queue would jam the tx path (tx
queue is full, new packets cannot be added to queue and dwc_txstart never
gets called).
This fatal mismatch appeared to be absolutely harmless, since both structs
have pointer to struct ifnet as their first member, and they both point to
the same ifnet. And the first member is the only one used from the argument.
When providing memory map information to userland, populate the vnode pointer
for tmpfs files. Set the memory mapping to appear as a vnode type, to match
FreeBSD 9 behavior.
This fixes the use of tmpfs files with the dtrace pid provider,
procstat -v, procfs, linprocfs, pmc (pmcstat), and ptrace (PT_VM_ENTRY).
Submitted by: Eric Badger <eric@badgerio.us> (initial revision)
Obtained from: Dell Inc.
PR: 198431
MFC after: 2 weeks
Reviewed by: jhb
Approved by: kib (mentor)
applying them to em(4).
Rely on iterations through the local timer, and the tx queue state to
determine if an actual hang has occurred. Any time a descriptor is used
(packet sent), the tx queue is flagged as busy. Then when txeof runs, it
either clears the flag when all is clean, or resets it to 1 if ANY are
cleaned, if nothing is cleaned it increments the flag.
Local timer simply checks to see if busy ever reaches MAX (10, which
is compile time configurable), and then sets it as HUNG, at that point
there is one more timer cycle in which to have any cleans, if not a
watchdog reset will occur.
Differential Revision: https://reviews.freebsd.org/D2019
Submitted by: jfv
Reviewed by: hiren
Obtained from: Intel Corporation
MFC after: 2 weeks
Relnotes: Yes
Sponsored by: Limelight Networks
stage processing is only allowed after the setup complete event has
been received. Else a race may occur and the OUT data can be corrupted.
While at it ensure resetting a FIFO has the required wait loop.
MFC after: 3 days
NOTE: This is a technology preview, while it has undergone
development testing, Intel has not yet completed full
validation of the feature. It is being integrated for
early access and customer testing.
NOTE: This is a technology preview, while it has undergone development
tests, Intel has not yet completed full validation of the feature.
It is being integrated for early access and customer testing.
tend to be invalid. On a Beaglebone Black, we get 8192 sectors per
track and that causes major breakages.
Differential Revision: D2646
Reviewed by: ian@ imp@
buildkernel run.
Some of them were write-only under some kernel options, e.g. variables
keeping values only used by CTR() macros. It costs nothing to the
code readability and correctness to eliminate the warnings in those
cases too by removing the local cached values used only for
single-access.
Review: https://reviews.freebsd.org/D2665
Reviewed by: rodrigc
Looked at by: bjk
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
DEBUG_FLAGS are set to DEBUG option value when kernel is built.
For example, it is -g in GENERIC config to have debug symbols.
Also DEBUG_FLAGS are used to determine if ctfconvert should keep
debug symbols.
Since we redefined DEBUG_FLAGS, debug symbols were always missing.
ctfconvert complains about it during kernel build.
It is incorrect to append DEBUG_FLAGS, since if DEBUG has no -g (or
similar), we'll have no debug symbols and ctfconvert will complain.
If it incorrect to always have -g in our DEBUG_FLAGS, since debug
symbols presence should be controllable by kernel config.
So, just add disabled by default addition of -DDEBUG=1 to CFLAGS.
Reviewed by: imp
Sponsored by: Solarflare Communications, Inc.
MFC after: 2 days
Differential Revision: https://reviews.freebsd.org/D2666
Leaf drivers should not import the PCI bus interface to add IOV handling.
Instead, move the IOV client methods to a separate kobj interface.
Differential Revision: https://reviews.freebsd.org/D2584
Reviewed by: rstone
- Updated all files with 2015 Avago copyright, and updated LSI's copyright
dates.
- Changed all of the PCI device strings from LSI to Avago Technologies (LSI).
- Added a sysctl variable to control how StartStopUnit behavior works. User can
select to spin down disks based on if disk is SSD or HDD.
- Inquiry data is required to tell if a disk will support SSU at shutdown or
not. Due to the addition of mpssas_async, which gets Advanced Info but not
Inquiry data, the setting of supports_SSU was moved to the
mpssas_scsiio_complete function, which snoops for any Inquiry commands. And,
since disks are shutdown as a target and not a LUN, this process was
simplified by basing it on targets and not LUNs.
- Added a sysctl variable that sets the amount of time to retry after sending a
failed SATA ID command. This helps with some bad disks and large disks that
require a lot of time to spin up. Part of this change was to add a callout to
handle timeouts with the SATA ID command. The callout function is called
mpssas_ata_id_timeout(). (Fixes PR 191348)
- Changed the way resets work by allowing I/O to continue to devices that are
not currently under a reset condition. This uses devq's instead of simq's and
makes use of the MPSSAS_TARGET_INRESET flag. This change also adds a function
called mpssas_prepare_tm().
- Some changes were made to reduce code duplication when getting a SAS address
for a SATA disk.
- Fixed some formatting and whitespace.
- Bump version of mps driver to 9.255.01.00-fbsd
PR: 191348
Reviewed by: ken, scottl
Approved by: ken, scottl
MFC after: 1 week
message synced to the changes in r283632, those changes are now backed out.
Another commit will be done that is exactly the same as r283632 except it will
have to correct commit message.
Approved by: ken, scottl, asomers, gibbs
amount of memory.
- Don't request segsize of BUS_SPACE_MAXSIZE_32BIT, when maxsize is
MCLBYTES.
With this change bwi_attach() can succeed on i386.
Submitted by: scottl
Smart NICs with firmware (eg wpi, iwn, the new atheros parts, the intel 7260
series, etc) support doing a lot of things in firmware. This includes but
isn't limited to things like scanning, sending probe requests and receiving
probe responses. However, net80211 doesn't know about any of this - it still
drives the whole scan/probe infrastructure itself.
In order to move towards suppoting smart NICs, the receive path needs to
know about the channel/details for each received packet. In at least
the iwn and 7260 firmware (and I believe wpi, but I haven't tried it yet)
it will do the scanning, power-save and off-channel buffering for you -
all you need to do is handle receiving beacons and probe responses on
channels that aren't what you're currently on. However the whole receive
path is peppered with ic->ic_curchan and manual scan/powersave handling.
The beacon parsing code also checks ic->ic_curchan to determine if the
received beacon is on the correct channel or not.[1]
So:
* add freq/ieee values to ieee80211_rx_stats;
* change ieee80211_parse_beacon() to accept the 'current' channel
as an argument;
* modify the iv_input() and iv_recv_mgmt() methods to include the rx_stats;
* add a new method - ieee80211_lookup_channel_rxstats() - that looks up
a channel based on the contents of ieee80211_rx_stats;
* if it exists, use it in the mgmt path to switch the current channel
(which still defaults to ic->ic_curchan) over to something determined
by rx_stats.
This is enough to kick-start scan offload support in the Intel 7260
driver that Rui/I are working on. It also is a good start for scan
offload support for a handful of existing NICs (wpi, iwn, some USB
parts) and it'll very likely dramatically improve stability/performance
there. It's not the whole thing - notably, we don't need to do powersave,
we should not scan all channels, and we should leave probe request sending
to the firmware and not do it ourselves. But, this allows for continued
development on the above features whilst actually having a somewhat
working NIC.
TODO:
* Finish tidying up how the net80211 input path works.
Right now ieee80211_input / ieee80211_input_all act as the top-level
that everything feeds into; it should change so the MIMO input routines
are those and the legacy routines are phased out.
* The band selection should be done by the driver, not by the net80211
layer.
* ieee80211_lookup_channel_rxstats() only determines 11b or 11g channels
for now - this is enough for scanning, but not 100% true in all cases.
If we ever need to handle off-channel scan support for things like
static-40MHz or static-80MHz, or turbo-G, or half/quarter rates,
then we should extend this.
[1] This is a side effect of frequency-hopping and CCK modes - you
can receive beacons when you think you're on a different channel.
In particular, CCK (which is used by the low 11b rates, eg beacons!)
is decodable from adjacent channels - just at a low SNR.
FH is a side effect of having the hardware/firmware do the frequency
hopping - it may pick up beacons transmitted from other FH networks
that are in a different phase of hopping frequencies.
Support 7xxx adapters including firmware-assisted TSO and VLAN tagging:
- Solarflare Flareon Ultra 7000 series 10/40G adapters:
- Solarflare SFN7042Q QSFP+ Server Adapter
- Solarflare SFN7142Q QSFP+ Server Adapter
- Solarflare Flareon Ultra 7000 series 10G adapters:
- Solarflare SFN7022F SFP+ Server Adapter
- Solarflare SFN7122F SFP+ Server Adapter
- Solarflare SFN7322F Precision Time Synchronization Server Adapter
- Solarflare Flareon 7000 series 10G adapters:
- Solarflare SFN7002F SFP+ Server Adapter
Support utilities to configure adapters and update firmware.
The work is done by Solarflare developers
(Andy Moreton, Andrew Lee and many others),
Artem V. Andreev <Artem.Andreev at oktetlabs.ru> and me.
Sponsored by: Solarflare Communications, Inc.
MFC after: 2 weeks
Causually read by: gnn
Differential Revision: https://reviews.freebsd.org/D2618
https://www.kernel.org/doc/Documentation/devicetree/bindings/leds/leds-gpio.txt
Without this booting the VSATV102 causes the blue "working" led to turn
off when the kernel starts up. With this the led (which is turned on by
the firmware) stays on since that's the default state specified in the FDT.
Expanded the meaning of the led_create_state state parameter in order
to implement support for "keep". The original values were:
== 0 Off
!= 0 On
The new values are:
== -1 don't change / keep current setting
== 0 Off
!= -1 && != 0 On
This should have no effect on acpi_asus_attach which only calls
led_create_state with state set to 1. Updated acpi_ibm_attach
in order to avoid surprises.
Differential Revision: https://reviews.freebsd.org/D2615
Submitted by: John Wehle
Reviewed by: gonzo, loos
years for head. However, it is continuously misused as the mpsafe argument
for callout_init(9). Deprecate the flag and clean up callout_init() calls
to make them more consistent.
Differential Revision: https://reviews.freebsd.org/D2613
Reviewed by: jhb
MFC after: 2 weeks
Kernel under stress load, mixed MC reboot and sfupdate really
generates TSO packet with RST flag.
It will generate many TCP packets with RST flag set.
May be RST flag should be set in the last segment only, but it could be
dropped. So, it is safer to keep the flag in all packets to be sure that
connection is reset.
Reviewed by: gnn
Sponsored by: Solarflare Communications, Inc.
MFC after: 2 days
Differential Revision: https://reviews.freebsd.org/D2609
files to vendor-provided ones. It should make easier to adopt platform
code to new revisions of hardware and to use DTS overlays for various
Beaglebone extensions (shields/capes).
Original dts filenames were not changed, they're now wrappers over dts
files provided by TI. So make sure you update .dtb files on your
devices as part of kernel update
GPIO addressing was changed: instead of one global /dev/gpioc0 there
are per-bank instances of /dev/gpiocX. Each bank has 32 pins so for
instance pin 121 on /dev/gpioc0 in old addressing scheme is now pin 25
on /dev/gpioc3
On Pandaboard serial console devices was changed from /dev/ttyu0 to
/dev/ttyu2 so you'll have to update /etc/ttys to get login prompt
on serial port in multiuser mode. Single user mode serial console
should work as-is
Differential Revision: https://reviews.freebsd.org/D2146
Reviewed by: rpaulo, ian, Michal Meloun, Svatopluk Kraus
Some FDT nodes have complex properties organized as a child sub-nodes
(e.g. timing for LCD panel) we need easy way to obtain handles for
these sub-nodes
