so there's no need to enable the RX of invalid frames just to do ANI.
The if_ath code and AR5212 ANI code setup the RX filter bits to enable
receiving OFDM/CCK errors if the device doesn't have the hardware
MIB counters. It isn't initialising it for the AR5416+ because all of
those chips have hardware MIB counters.
This fixes the odd (and performance affecting!) situation where if ani
is enabled (via sysctl dev.ath.X.intmit) then suddenly there's be a very
large volume of phy errors - which is good to track, but not what was
intended. Since each PHY error is a received (0 length) frame, it can
significantly tie up the RX side of things.
It's still not ready for prime-time - there's some TX niggles with these 11n
cards that I'm still trying to wrap my head around, and AMPDU-TX is just not
implemented so things will come to a crashing halt if you're not careful.
"extended capabilities" to refer to the new set of capability structures
starting at offset 0x100 in config space for PCI-express devices. For now
both function names will still work. I will merge this to older branches
to ease driver portability, but 9.0 will ship with a new pci_find_extcap()
function that locates extended capabilities instead.
Reviewed by: imp
MFC after: 1 week
This fix modifies the const addac initval array, rather than modifying
a local copy. It means that running >1 AR9160 on a board may prove to
be unpredictable.
The AR5416 init path also does something similar, so supporting
>1 AR5416 of different revisions could cause problems.
The later fix will be to create a private copy of the Addac data
for the AR5416, AR9160 (and AR9100 when it's merged in) and then
modify that as needed.
Obtained From: Linux ath9k
I found this when trying to figure out why the RX PHY error count
didn't match the OFDM error count ANI was using. It turns out
there was two problems:
* What this commit addresses - using the wrong mask for OFDM errors,
and
* The RX filter is set incorrectly after a channel scan (at least)
even if interference mitigation is enabled by default.
ANI is still disabled by default for the AR5416 and later chips.
bring it in line with the rest of the register initialisation.
I've verified that the 2/5ghz board values written to the
chip match what was previously written.
* add pspoll/uapsd queue setup defaults;
* enable the exponential backoff window rather than the random
backoff window when doing TX contention management.
would be a problem, make sure it isn't overwritten by whatever is in
there at cold reset.
This brings the > ar5416 init path treatment of AR_MISC_MODE.
report descriptor information, sysctl utility
will show it for us.
- Modify sysctl node description to make it more
understanable.
Found by: Alexander Best <arundel@freebsd.org>
Submitted by: Eygene Ryabinkin <rea@freebsd.org>
MFC after: 14 days
Approved by: thompsa (mentor)
value is updated after that we read it in the queue-head. This patch can
fix problems with BULK timeouts. The issue was found on a Nvidia chipset.
MFC after: 14 days
Approved by: thompsa (mentor)
* Pull out the static rix stuff into a different function
* I know this may slightly drop performance, but check if a static
rix is needed before each packet TX.
* Whilst I'm at it, add a little extra debugging to the rate
control stuff to make it easier to follow what's going on.
Give it a good go (32 attempts) and then print out a warning that's
going to occur whether HAL debugging is enabled or not. Then don't
abort the radio setup; just continue merrily along.
This should fix the issue that users were having where scanning would
occasionally fail on the active channel, causing traffic to cease
until the radio scanned again.
not needed.
These calibrations are only applicable if the chip operating mode
engages both interleaved RX ADCs (ie, it's compensating for the
differences in DC gain and DC offset -between- the two ADCs.)
Otherwise the chip reads values of 0x0 for the secondary ADC
(as I guess it's not enabled here) and thus writes potentially
bogus info into the chip.
I've tested this on the AR9160 and AR9280; both behave themselves
in 11g mode with these calibrations disabled.
for fixing them based on the ath9k related TXQ fixes.
I've done this so people can go over the history of the diffs to the original
AR5212 routines (which AR5416 and later chips use) to see what's changed.
enables broadcast filtering. Make sure to clear the bit to receive
broadcast frames. While I'm here rename the bit definition to
reflect reality.
Reported by: brad@OpenBSD
MFC after: 1 week
This commit really is "fix the OFDM duration calculation to match reality when
running in 802.11g mode."
The AR5212 init vals set AR_MISC_MODE to 0x0 and all the bits that can be set are
set through code.
The AR5416 and later initvals set AR_MISC_MODE to various other values (with
the AR5212 AR_MISC_MODE options cleared), which include AR_PCU_CCK_SIFS_MODE .
This adds 6uS to SIFS on non-CCK frames when transmitting.
This fixes the issue where _DATA_ 802.11g OFDM frames were being TX'ed with
the ACK duration set to 38uS, not 44uS as on the AR5212 (and other devices.)
The AR5212 TX pathway obeys the software-programmed duration field in the packet,
but the 11n TX pathway overrides that with a hardware-calculated duration. This
was getting it wrong because of the above AR_MISC_MODE setting. I've verified
that 11g data OFDM frames are now being TXed with the correct ACK+SIFS duration
programmed in.
Since ath9k does some slightly different bit fiddling when setting up
the TX queues, it may that the TX queue setup/reset functions will need
overriding later on.
been undergoing test for some weeks. This improves the RX
mbuf handling to avoid system hang due to depletion. Thanks
to all those who have been testing the code, and to Beezar
Liu for the design changes.
Next the igb driver is updated for similar RX changes, but
also to add new features support for our upcoming i350 family
of adapters.
MFC after a week
chipsets that do not have an HT slave at 0:0:0:0. The Linux quirk is
actually specific to Nvidia chipsets and the check I had added was in
the wrong place.
Prodded by: nathanw
- Always enable the HyperTransport MSI mapping window for HyperTransport
to PCI bridges (these show up as HyperTransport slave devices).
The mapping windows in PCI-PCI bridges are enabled by existing code
in the PCI-PCI bridge driver as MSI requests propagate up the device
tree, but Host-PCI bridges don't really show up in that tree.
- If the PCI device at domain 0 bus 0 slot 0 function 0 is not a
HyperTransport device, then blacklist MSI on any other HT devices in
the system. Linux has a similar quirk.
PR: kern/155442
Tested by: Zack Dannar zdannar of gmail
MFC after: 1 week
With this change, driver may not notice updated descriptor status
change when bounce buffers are active. However, rxeof() in next run
will handle the synchronization.
Change dc_rxeof() a bit to return the number of processed frames in
RX descriptor ring. Previously it returned the number of frames
that were successfully passed to upper stack which in turn means it
ignored frames that were discarded due to errors. The number of
processed frames in RX descriptor ring is used to detect whether
driver is out of sync with controller's current descriptor pointer.
Returning number of processed frames reduces unnecessary (probably
wrong) re-synchronization.
Reviewed by: marius
This does a few things in particular:
* Abstracts out the gain control settings into a separate function;
* Configure antenna diversity, LNA and antenna gain parameters;
* Configure ob/db entries - the later v4k EEPROM modal revisions have
multiple OB/DB parameters which are used for some form of
calibration. Although the radio does have defaults for each,
the EEPROM can override them.
This resolves the AR2427 related issues I've been seeing and makes
it stable at all 11g rates for both TX and RX.
The offsets didn't match the assumption that nfarray[] is ordered by the
chainmask bits and programmed via the register order in ar5416_cca_regs[].
This repairs that damage and ensures that chain 1 is programmed correctly.
(And extension channels will now be programmed correctly also.)
This fixes some of the stuck beacons I've been seeing on my AR9160/AR5416
setups - because Chain 1 would be programmed -80 or -85 dBm, which is
higher than the actual noise floor and thus convincing the radio that
indeed it can't ever transmit.
rather than duplicating them for the v14 (ar5416+) and v4k (ar9285) codebases.
Further chipsets (eg the AR9287) have yet another EEPROM format which will use
these routines to calculate things.
to the TX closed-loop power control registers.
* Modify a couple of functions to take the register chain number,
rather than the regChainOffset value. This allows for the
register chain to be logged.
also does this for sound drivers it's probably not necessary for all
combinations of controllers and drivers. However, given that our sound
drivers completely lack bus_dmamap_sync(9) calls this at least serves
as a workaround when enabling use of the IOMMU streaming buffers on
sparc64 and generally for arm and mips.
MFC after: 2 weeks
Linux ath9k.
The ath9k ar9002_hw_init_cal() isn't entirely clear about what
is supposed to be called for what chipsets, so I'm ignoring the
rest of it and just porting the AR9285 init cal path as-is and
leaving the rest alone. Subsequent commits may also tidy up the
Merlin (AR9285) and other chipset support.
Obtained from: Linux ath9k
The ath9k driver has a unified boundary/pdadc function, whereas
ours is split into two (one for each EEPROM type.) This is why
the AR9280 check is done here where we could safely assume it'll
always be AR9280 or later.
this is incorrect for Kite (AR9285) and any future chipsets that
override the EEPROM related routines.
It meant that a direct call to set the TX power would call the v14 EEPROM
AR5416/AR9280 calibration routines, rather than the v4k EEPROM routines
for the AR9285. It thus read the incorrect values from the EEPROM and
programmed garbage PDADC and TX power values into the hardware.
It looks like these apply in both open and closed loop TX power control,
but the only merlin boards i have either have OL -or- a non-default power
offset, not both.
to both make things clearer, and to make it easier to write userland
code which pulls in these definitions without needing to pull in the
rest of the HAL.
This stuff should be deprecated at some point in the future once
the net80211 regulatory domain support encapsulates all of the
defintions here.
This is something bus clock related from what I can gather. It is needed for
the AR9220 based Ubiquiti SR71-12 and SR71-15 Mini-PCI NICs.
(Note: those NICs don't work right now because of earlier changes to handle
power table offset correctly. That'll be resolved in a follow-up commit.)
Merlin (ar9280) and later were full-reset if they're doing open-loop TX
power control but the TSF wasn't being saved/restored.
Add ar5212SetTsf64() which sets the 64 bit TSF appropriately.
value. Controllers that always require "store and forward" mode(
Davicom and PNIC 82C168) have no way to recover from TX underrun
except completely reinitializing hardware. Previously only Davicom
was reinitialized and the TX FIFO threshold was changed not to use
"store and forward" mode after reinitialization since the default
FIFO threshold value was 0. This effectively disabled Davicom
controller's "store and forward" mode once it encountered TX
underruns. In theory, this can cause watchodg timeouts.
Intel 21143 controller requires TX MAC should be idle before
changing TX FIFO threshold. So driver tried to disable TX MAC and
checked whether it saw the idle state of TX MAC. Driver should
perform full hardware reinitialization on failing to enter to idle
state and it should not touch TX MAC again once it performed full
reinitialization.
While I'm here remove resetting TX FIFO threshold to 0 when
interface is put into down state. If driver ever encountered TX
underrun, it's likely to trigger TX underrun again whenever
interface is brought to up again. Keeping old/learned TX FIFO
threshold value shall reduce the chance of seeing TX underrns in
next run.
generally tidy up the TX power programming code.
Enforce that the TX power offset for Merlin is -5 dBm, rather than
any other value programmable in the EEPROM. This requires some
further code to be ported over from ath9k, so until that is done
and tested, fail to attach NICs whose TX power offset isn't -5
dBm.
This improves both legacy and HT transmission on my merlin board.
It allows for stable MCS TX up to MCS15.
Specifics:
* Refactor out a bunch of the TX power calibration code -
setting/obtaining the power detector / gain boundaries,
programming the PDADC
* Take the -5 dBm TX power offset into account on Merlin -
"0" in the per-rate TX power register means -5 dBm, not
0 dBm
* When doing OLC
* Enforce min (0) and max (AR5416_MAX_RATE_POWER) when fiddling
with the TX power, to avoid the TX power values from wrapping
when low.
* Implement the 1 dBm cck power offset when doing OLC
* Implement temperature compensation for 2.4ghz mode when doing OLC
* Implement an AR9280 specific TX power calibration routine which
includes the OLC twiddles, leaving the earlier chipset path
(AR5416, AR9160) alone
Whilst here, use these refactored routines for the AR9285 TX power
calibration/programming code and enforce correct overflow/underflow
handling when fiddling with TX power values.
Obtained from: linux ath9k
the ataahci(4) and atamarvell(4) drivers share it between the host and
the controller.
- Spell some zeros as BUS_DMA_WAITOK when used as bus_dmamem_alloc() flags.
MFC after: 2 weeks
coherent.
- Add some missing bus_dmamap_sync() calls. This includes putting such
calls before calling reply handlers instead of calling bus_dmamap_sync()
for the request queue from individual reply handlers as these handlers
generally read back updates by the controller.
Tested on amd64 and sparc64.
MFC after: 2 weeks
It defaults to -5 dBm for eeproms earlier than v21.
This apparently only applies to Merlin (AR9280) or later,
earlier 11n chipsets have a power table offset of 0.
All the code in ath9k which checks the power table offset
and takes it into account first ensures the chip is
Merlin or later.
The earlier way of doing debugging would evaluate the function parameters
before calling the HALDEBUG. In the case of detailed register debugging
would mean a -lot- of unneeded register IO and other stuff was going on.
This method evaluates the ath_hal_debug variable before the function
parameters are evaluated, drastically reducing the amount of overhead
enabling HAL debugging during compilation.
- everything related to LRO should be in #ifdef INET blocks
- reorder sge_iq's fields so that the most frequently used are all together
- pull all rx code into t4_intr_data directly
- let go of the ingress queue lock when passing up data
- refill the freelist only if it is short of at least 32 buffers
determining whether to use MRR or not.
It uses the 11g protection mode when calculating 11n related stuff, rather
than checking the 11n protection mode.
Furthermore, the 11n chipsets can quite happily handle multi-rate retry w/
protection; the TX path and rate control modules need to be taught about
that.
* change the BB gating logic to explicitly define which chips are covered;
the ath9k method isn't as clear.
* don't disable the BB gating for now, the ar5416 initvals have it, and the
ar9160 initval sets it to 0x0. Figure out why before re-enabling this.
* migrate the Merlin (ar9280) applicable WAR from the Kite (ar9285) code
(which won't get called for Merlin!) and stuff it in here.
* add dot11rate_label() which returns Mb or MCS based on legacy or HT
* use it everywhere dot11rate() is used
* in the "current selection" part at the top of the debugging output,
otuput what the rate itself is rather than the rix. The rate index
(rix) has very little meaning to normal humans who don't know how
to find the PHY settings for each of the chipsets; pointing out the
rix rate and type is likely more useful.
These flags are just plain wrong - they're the node flags from negotiation,
not the configured flags. I'll jump in later on and figure out exactly
what should be done to properly set these two flags when in both STA mode
(ie, what the AP says is possible and what's configured) and AP mode
(ie, where the AP has a configuration, but then negotiates what's possible
with each node, so per-node configuration can and will differ.)
This allows the 11n 2.4ghz/ht20 mode to associate (but perform poorly still)
and exchange MCS rates with atheros reference APs and a Cisco/Linksys
E3000 AP.
operation. Previously ownership was transferred to hardware before
setting address of new RX buffer such that it was possible for
hardware to use wrong RX buffer address.
While here keep compiler from re-ordering instructions by declaring
descriptor members volatile. Memory barriers would do the same job
but volatile is supposed to be cheaper than using memory barriers,
especially on MP systems.
Submitted by: marius
MFC after: 1 week
mps.c: Hide the 'out of chain frames' warning behind MPS_INFO.
mps_sas.c: Hide the SIM queue freeze/unfreeze messages behind MPS_INFO.
mpsvar.h: Bump the number of chain frames from 1024 to 2048. From
testing, it looks like this makes it less likely that we'll
run out of chain frames, and it doesn't cost much memory
(32K).
MFC after: 3 days
means of allowing vendor specific interface class for audio and MIDI devices.
- Add new quirks for this. The vendor and product list in OpenBSD's
dev/usb/umidi_quirks.c was used as reference.
MFC after: 14 days
Approved by: thompsa (mentor)
causing the size calculation to be truncated to the size of an int
(32-bits on all current architectures).
Submitted by: Anish akgupt3 of gmail
MFC after: 1 week
link flips during alias address insertion or dhclient operation.
While I'm here remove dc_reset() in DC_ISR_BUS_ERR case. Device is
fully reinitialized again in dc_init_locked().
* Turn ath_tx_calc_ctsduration() into a function that
returns the ctsduration, or -1 for HT rates;
* add a printf() to ath_tx_calc_ctsduration() which will be
very loud if somehow that function is called with an MCS
rate;
* Add ath_tx_get_rtscts_rate() which returns the RTS/CTS
rate to use for the given data rate, incl. the short
preamble flag;
* Only call ath_tx_calc_ctsduration() for non-11n chipsets;
11n chipsets don't require the rtscts duration to be
calculated.
It's used to calculate:
* the initial per-rate entries for short/long preamble ACK durations;
* packet durations for TDMA slot decisions;
* RTS/CTS protection durations;
* updating the duration field in the 802.11 frame header
This way invalid durations will generate a warning, prompting for it to be
fixed.
respectively and fix all bus_dma(9) issues seen when bounce buffers
are used.
o Setup frame handling had no bus_dmamap_sync(9) which prevented
driver from configuring RX filter. Add missing bus_dmamap_sync(9)
in both dc_setfilt_21143()/dc_setfilt_xircom() and dc_txeof().
o Use bus_addr_t for DMA segment instead of using u_int32_t.
o Introduce dc_dma_alloc()/dc_dma_free() functions to allocate/free
DMA'able memory.
o Create two DMA descriptor list for each TX/RX lists. This change
will minimize the size of bounce buffers that would be used in
each TX/RX path. Previously driver had to copy both TX/RX lists
when bounce buffer is active.
o 21143 data sheet says descriptor list requires 4 bytes alignment.
Remove PAGE_SIZE alignment restriction and use
sizeof(struct dc_dec).
o Setup frame requires 4 bytes alignment. Remove PAGE_SIZE
alignment restriction and use sizeof(struct dc_dec).
o Add missing DMA map unload for both setup frame and TX/RX
descriptor list.
o Overhaul RX handling logic such that make driver always allocate
new RX buffer with dc_newbuf(). Previously driver allowed to
copy received frame with m_devget(9) after passing the
descriptor ownership to controller. This can lead to passing
wrong frame to upper stack.
o Introduce dc_discard_rxbuf() which will discard received frame
and reuse loaded DMA map and RX mbuf.
o Correct several wrong bus_dmamap_sync(9) usage in dc_rxeof and
dc_txeof. The TX/RX descriptor lists are updated by both driver
and HW so READ/WRITE semantics should be used.
o If driver failed to allocate new RX buffer, update if_iqdrops
counter instead of if_ierrors since driver received the frame
without errors.
o Make sure to unload loaded setup frame DMA map in dc_txeof and
clear the mark of setup frame of the TX descriptor in dc_txeof().
o Add check for possible TX descriptor overruns in dc_encap() and
move check for free buffer to caller, dc_start_locked().
o Swap the loaded DMA map and the last DMA map for multi-segmented
frames. Since dc_txeof() assumes the last descriptor of the
frame has the DMA map, driver should swap the first and the last
DMA map in dc_encap(). Previously driver tried to unload
not-yet-loaded DMA map such that the loaded DMA map was not
unloaded at all for multi-segmented frames.
o Rewrite DC_RXDESC/DC_TXDESC macro to simpler one.
o Remove definition of ETHER_ALIGN, it's already defined in
ethernet.h.
With this changes, dc(4) works with bounce buffers and it shall
also fix issues which might have shown in PAE environments.
Tested by: marius
Previously dc(4) always checked whether there is pending interrupts
and this consumed a lot of CPU cycles in interrupt handler. Limit
the number of processing for TX/RX frames to 16. Also allow sending
frames in the loop not to starve TX under high RX load.
Reading DC_ISR register should be protected with driver lock,
otherwise interrupt handler could be run(e.g. link state change)
before the completion of dc_init_locked().
While I'm here remove unneeded code.
as well as controller has enough free TX descriptors.
Remove check for number of queued frames before attempting to
transmit. I guess it was added to allow draining queued frames
even if there is no link. I'm under the impression this type of
check should be done in upper layer. No other drivers in tree do
that.
ownership to controller before completion of access to the
descriptor. Driver is faking up status word so it should not give
ownership to controller until it completes RX processing.
request TX completion interrupt for every 8-th frames. Previously
dc(4) requested TX completion interrupt if number of queued TX
descriptors is greater than 64. This caused a lot of TX completion
interrupt under high TX load once driver queued more than 64 TX
descriptors. It's quite normal to see more than 64 queued TX
descriptors under high TX load.
This change reduces the number of TX completion interrupts to be
less than 17k under high TX load. Because this change does not
generate TX completion interrupt for each frame, add reclaiming
transmitted buffers in dc_tick not to generate false watchdog
timeouts.
While I'm here add check for queued descriptors in dc_txeof() since
there is no more work to do when there is no pending descriptors.
When the driver ran out of DMA chaining buffers, it kept the timeout for
the I/O, and I/O would stall.
The driver was not freezing the device queue on errors.
mps.c: Pull command completion logic into a separate
function, and call the callback/wakeup for commands
that are never sent due to lack of chain buffers.
Add a number of extra diagnostic sysctl variables.
Handle pre-hardware errors for configuration I/O.
This doesn't panic the system, but it will fail the
configuration I/O and there is no retry mechanism.
So the device probe will not succeed. This should
be a very uncommon situation, however.
mps_sas.c: Freeze the SIM queue when we run out of chain
buffers, and unfreeze it when more commands
complete.
Freeze the device queue when errors occur, so that
CAM can insure proper command ordering.
Report pre-hardware errors for task management
commands. In general, that shouldn't be possible
because task management commands don't have S/G
lists, and that is currently the only error path
before we get to the hardware.
Handle pre-hardware errors (like out of chain
elements) for SMP requests. That shouldn't happen
either, since we should have enough space for two
S/G elements in the standard request.
For commands that end with
MPI2_IOCSTATUS_SCSI_IOC_TERMINATED and
MPI2_IOCSTATUS_SCSI_EXT_TERMINATED, return them
with CAM_REQUEUE_REQ to retry them unconditionally.
These seem to be related to back end, transport
related problems that are hopefully transient. We
don't want to go through the retry count for
something that is not a permanent error.
Keep track of the number of outstanding I/Os.
mpsvar.h: Track the number of free chain elements.
Add variables for the number of outstanding I/Os,
and I/O high water mark.
Add variables to track the number of free chain
buffers and the chain low water mark, as well as
the number of chain allocation failures.
Add I/O state flags and an attach done flag.
MFC after: 3 days
the controller firmware will return all of our commands. Instead, keep
track of outstanding I/Os and return them to CAM once device removal
processing completes.
mpsvar.h: Declare the new "io_list" in the mps_softc.
mps.c: Initialize the new "io_list" in the mps softc.
mps_sas.c: o Track SCSI I/O requests on the io_list from the
time of mpssas_action() through mpssas_scsiio_complete().
o Zero out the request structures used for device
removal commands prior to filling them out.
o Once the target reset task management function completes
during device removal processing, assume any SCSI I/O
commands that are still oustanding will never return
from the controller, and process them manually.
Submitted by: gibbs
MFC after: 3 days
- Use the USB stack's builtin clear-stall feature.
- Wrap some long lines.
- Use memcpy() instead of bcopy().
- Use memset() instead of bzero().
- Tested applications:
/usr/ports/audio/fluidsynth
MFC after: 7 days
Approved by: thompsa (mentor)
frame in DM910x controllers. In r67595(more than 10 years ago) it
was replaced to use "Store and Forward" mode and made controller
generate TX completion interrupt for every frame.
any other media configuration. Otherwise some 21143 controller
cannot establish a link. While I'm here remove the PHY
initialization code in dc_setcfg(). Since dc_setcfg() is called
whenever link state is changed, having the PHY initialization code
in dc_setcfg() resulted in continuous link flips.
After driver resets SIA, use default SIA transmit/receive
configuration instead of disabling autosense/autonegotiation.
Otherwise, controller fails to establish a link as well as losing
auto-negotiation capability. For manual media configuration, always
configure 21143 controller with specified media to ensure media
change. This change makes ANA-6922 establish link with/without
auto-negotiation.
While I'm here be more strict on link UP/DOWN detection logic.
Many thanks to marius who fixed several bugs in initial patch and
even tested the patch on a couple of dc(4) controllers.
PR: kern/79262
Reviewed by: marius
Tested by: marius
port, copy SROM information from base softc as well and run SROM
parser again. This change is necessary for some dual port
controllers to make dc(4) correctly detect PHY media based on first
port configuration table.
While I'm here add a check for validity of the base softc before
duplicating SROM contents from base softc. If driver failed to
attach to the first port it can access invalid area.
PR: kern/79262
Reviewed by: marius
as they're likely not entirely correct, but they give people something
to toy with to compare behaviour/performance.
Disable the anti-noise part, as this apparently interferes with
RIFS. I haven't verified this.
packet duration for the ath_rate_sample module.
This doesn't affect the packet TX at all; only how much time the
sample rate module attributes to a completed TX.
