When module is reloaded, device may fail to work, with messages:

[  342.211926] phy40 -> rt2x00lib_rxdone_read_signal: Warning - Frame received with unrecognized signal, mode=0x0000, signal=0x0059, type=2.
[  342.314254] phy40 -> rt2x00lib_rxdone_read_signal: Warning - Frame received with unrecognized signal, mode=0x0000, signal=0x004a, type=2.
[  342.416458] phy40 -> rt2x00lib_rxdone: Warning - Wrong frame size 3183 max 2432.
[  342.518605] phy40 -> rt2x00lib_rxdone_read_signal: Warning - Frame received with unrecognized signal, mode=0x0000, signal=0x00c9, type=2.
[  342.620836] phy40 -> rt2x00lib_rxdone_read_signal: Warning - Frame received with unrecognized signal, mode=0x0000, signal=0x00ae, type=1.
[  342.723201] phy40 -> rt2x00lib_rxdone: Warning - Wrong frame size 0 max 2432.
[  342.825399] phy40 -> rt2x00lib_rxdone: Warning - Wrong frame size 0 max 2432.
[  342.927624] phy40 -> rt2x00lib_rxdone: Warning - Wrong frame size 0 max 2432.
[  343.029804] phy40 -> rt2x00lib_rxdone: Warning - Wrong frame size 2491 max 2432.
[  343.132008] phy40 -> rt2x00lib_rxdone: Warning - Wrong frame size 2576 max 2432.
[  343.234326] phy40 -> rt2x00lib_rxdone_read_signal: Warning - Frame received with unrecognized signal, mode=0x0000, signal=0x004c, type=1.
[  343.438723] phy40 -> rt2x00lib_rxdone_read_signal: Warning - Frame received with unrecognized signal, mode=0x0000, signal=0x00e6, type=1.

Whereas replugging device make it functional. To solve that problem
force reset device during probe.

With patch messages are gone. Unfortunately device may sometimes
still does not operate correctly after module reload (fail to receive
data after associate), but such cases are rarer than without the patch.
Signed-off-by: NStanislaw Gruszka <stf_xl@wp.pl>
Acked-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Patch:
  rt2x00: Make rt2x00_queue_entry_for_each more flexible
  commit: 10e11568

introduced a severe regression on the throughput
for USB hardware. It turns out that the exiting of
the rt2x00queue_for_each_entry() was done too early.

The exact cause for this regression is unknown,
but by disabling the premature exiting of the loop
seems to resolve the issue.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Reported-by: NYasushi SHOJI <yashi@atmark-techno.com>
Reported-by: NBalint Viragh <bviragh@dension.com>
Tested-by: NBalint Viragh <bviragh@dension.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add recycling functionality to rt2x00usb_register_read_async.
When the callback function returns true, resubmit the urb to
read the register again.

This optimizes the rt2800usb driver when multiple TX status reports
are pending in the register, because now we don't need to allocate
the rt2x00_async_read_data and urb structure each time.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Both USB and PCI drivers allow a system administrator to dynamically add
USB/PCI IDs to the device table that a driver supports via the
/sys/bus/{usb,pci,pci_express}/drivers/<driver-name>/new_id files.

However, for the rt2x00 drivers using this method currently crashes the
system with a NULL pointer failure.

This is due to the set-up of rt2x00 where the probe functions require a
rt2x00_ops structure in the driver_info field of the probed device. As
this field is empty for the dynamically added devices this fails for
these devices.

Fix this by introducing driver-specific probe wrappers that do nothing
but calling the bus-specific probe functions with the rt2x00_ops structure
as an argument, rather than depending on the driver_info field.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When powersaving is enabled, assocaition times are very high
(for WPA2 networks, the time can easily be around the 3 seconds).

This is caused, because the flushing of the queues takes
too much time. Without the flushing callback mac80211 assumes
a timeout of 100ms while scanning. Limit all flush waiting
loops to the same maximum.

We can apply this maximum by passing the drop status to the
driver, which makes sure the driver performs extra actions
during the waiting for the queue to become empty.

After these changes, association times fall within the
healthy range of ~0.6 seconds with powersaving enabled.
The difference between association time between powersaving
enabled and disabled is now only ~0.1 second (which can also
be due to the measuring method).
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

TX status is reported by the hardware when a packet has been
sent (or after TX failed after possible retries), which is some
time after the DMA completion.  Since the rt2800usb hardware can
not signal interrupts we have to use a timer, otherwise the
TX status would only be read by the next packet's TX DMA
completion, or by the watchdog thread.
Signed-off-by: NJohannes Stezenbach <js@sig21.net>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add a timestamp to each queue entry which is updated whenever
the status of the entry changes, and remove the per-queue
timestamps.  The previous check was incorrect and caused both
false positives and false negatives.

With the corrected check it comes apparent that the TX status
usually times out on rt2800usb unless there is sufficient traffic
(i.e. the next TX will complete the previous TX status).
Signed-off-by: NJohannes Stezenbach <js@sig21.net>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Trying to fix the "TX status report missed" warnings
by reading the TX_STA_FIFO entries as quickly as possible.
The TX_STA_FIFO is too small in hardware, thus reading
it only from the workqueue is too slow and entries get lost.

Start an asynchronous read of the TX_STA_FIFO directly from
the TX URB completion callback (atomic context, thus it cannot
use the blocking rt2800_register_read()). If the async
read returns a valid FIFO entry, it is pushed into a larger
FIFO inside struct rt2x00_dev, until rt2800_txdone() picks
it up.

A .tx_dma_done callback is added to struct rt2x00lib_ops
to trigger the async read from the URB completion callback.
Signed-off-by: NJohannes Stezenbach <js@sig21.net>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Allow passing a void pointer to rt2x00_queue_entry_for_each which in
turn in provided to the callback function.

Furthermore, allow the callback function to stop processing by returning
true. And also notify the caller of rt2x00_queue_entry_for_each if the
loop was canceled by the callback.

No functional changes, just preparation for an upcoming patch.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The number of flags defined for the rt2x00dev->flags field,
has been growing over the years. Currently we are approaching
the maximum number of bits which are available in the field.

A secondary problem, is that one part of the field are initialized only
during boot, because the driver requirements are initialized or device
requirements are loaded from the EEPROM. In both cases, the flags are
fixed and will not change during device operation. The other flags are
the device state, and will change frequently. So far this resulted in the fact
that for some flags, the atomic bit accessors are used, while for the others
the non-atomic variants are used.

By splitting the flags up into a "flags" and "cap_flags" we can put all flags
which are fixed inside "cap_flags". This field can then be read non-atomically.
In the "flags" field we keep the device state, which is going to be read atomically.

This adds more room for more flags in the future, and sanitizes the field access methods.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

The TX/RX work structures must be able to run independently
of other workqueues. This is because mac80211 might use
the flush() callback function from various context, which depends
on the TX/RX work to complete while the main thread is blocked
(until the the TX queues are empty).

This should reduce the number of  'Queue %d failed to flush' warnings.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The Queue names were incorrectly copied from the legacy drivers,
as a result the queue names were inversed to what was expected.

This renames the queues using this mapping:
	QID_AC_BK -> QID_AC_VO (priority 0)
	QID_AC_BE -> QID_AC_VI (priority 1)
	QID_AC_VI -> QID_AC_BE (priority 2)
	QID_AC_VO -> QID_AC_BK (priority 3)

Note that this was a naming problem only, which didn't affect
the assignment of frames to their respective queues.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add a queue entry flag ENTRY_DATA_STATUS_PENDING,
which can be used to indicate a queue entry has
returned from the hardware and is waiting for
status processing. Using this flag we can add
some extra sanity checks to prevent queue corruption.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add the rt2x00_dmastart function to rt2x00lib which
marks the queue_entry as "owned by device", and increased
the Q_INDEX number.

This cleanups up the index handling by rt2x00lib which
at until so far used hackish approaches to keep the
RX queue index numbering sane.

The rt2x00pci.c changes are from Helmut Schaa
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add a new command to the queue handlers: "flush",
this moves the flush() callback from mac80211
into rt2x00queue and adds support for flushing
the RX queue as well.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Add wrapper functions in rt2x00queue.c to
start & stop queues. This control must be protected
using a mutex.

Queues can also be paused which will halt the flow
of packets between the driver and mac80211. This doesn't
require a mutex protection.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

As part of the queue refactoring, change the queue callback
function names to have 3 different actions: start, kick & stop.

We can now also remove the STATE_RADIO_RX_ON/STATE_RADIO_RX_OFF
device_state flags, and replace the usage with using the
start_queue/stop_queue callback functions.
This streamlines the RX queue handling to the
similar approach as all other queues.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

As part of the queue refactoring, we now introduce
3 queue commands: start, kick, stop.

 - Start: will enable a queue, for TX this will
   not mean anything, while for beacons and RX
   this will update the registers to enable the queue.
 - Kick: This will kick all pending frames to
   the hardware. This is needed for the TX queue
   to push all frames to the HW after the queue
   has been started
 - Stop: This will stop the queue in the hardware,
   and cancel any pending work (So this doesn't
   mean the queue is empty after a stop!).

Move all code from the drivers into the appropriate
functions, and link those calls to the old rt2x00lib
callback functions (we will fix this later when we
refactor the queue control inside rt2x00lib).
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Signed-off-by: NJohannes Stezenbach <js@sig21.net>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When an rt2x00 USB device is unplugged while in use, it reliably
hangs the whole system.  After some time the watchdog prints:

BUG: soft lockup - CPU#0 stuck for 64s! [kworker/u:0:5]
...
[<c01a88d8>] (usb_submit_urb+0x0/0x2ac) from [<bf0e752c>] (rt2x00usb_kick_rx_entry+0xb4/0xe8 [rt2x00usb])
[<bf0e7478>] (rt2x00usb_kick_rx_entry+0x0/0xe8 [rt2x00usb]) from [<bf0e7588>] (rt2x00usb_clear_entry+x28/0x2c [rt2x00usb])
[<bf0e7560>] (rt2x00usb_clear_entry+0x0/0x2c [rt2x00usb]) from [<bf0d5bc4>] (rt2x00lib_rxdone+0x2e0/0x2f8 [rt2x00lib])
[<bf0d58e4>] (rt2x00lib_rxdone+0x0/0x2f8 [rt2x00lib]) from [<bf0e7e00>] (rt2x00usb_work_rxdone+0x54/0x74 [rt2x00usb])
[<bf0e7dac>] (rt2x00usb_work_rxdone+0x0/0x74 [rt2x00usb]) from [<c00542b4>] (process_one_work+0x20c/0x35c)

Clear the DEVICE_STATE_PRESENT flag when usb_submit_urb()
returns -ENODEV to fix this.
Signed-off-by: NJohannes Stezenbach <js@sig21.net>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

By not scheduling the TX/RX completion worker threads
when Radio is disabled, or hardware has been unplugged,
the queues cannot be completely cleaned.

This causes crashes when the hardware has been unplugged while
the radio is still enabled.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

When the TX status handler failed to clear the queue
in rt2x00usb_watchdog_tx_dma() we shouldn't use a failsave
to use the rt2x00usb txdone handler.

If a driver has overriden the txdone handler it must make
sure the txdone handler is capable of cleaning up the queue itself.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Rename rt2x00queue_timeout to rt2x00queue_status_timeout to
better describe what is actually timing out (note that
we already have a rt2x00queue_dma_timeout).
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

kill_urb guarentees that when the function returns, the URB has
been fully killed. This means we don't need the extra sleeping
after the call to kill_urb.

kill_urb can however also guarentee the submit_urb to fail, as
a result, we must catch the return value from submit_urb an
correctly mark the entry as owned by the driver, and the
status as broken.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The currently used watchdog functions cannot be applied
to empty queues.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

All access to the queue_entry->flags can be done concurrently,
so all flags must use the atomic operators. On most locations
this was already done, so just fix the last few non-atomic
versions.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

A lot of functions accept a struct rt2x00_dev combined with
either a struct queue_entry or struct data_queue argument.
This can be simplified by only passing on the queue/entry
argument.

In cases where rt2x00_dev and a sk_buff are send together,
we can send the queue_entry instead.

rt2x00usb_alloc_urb and rt2x00usb_free_urb have a bit
of vague naming. Instead they allocate all the data which
belongs to a rt2x00 data queue entry.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

rt2x00usb_watchdog_reset_tx performs the same task
as rt2x00usb_kill_tx_queue, with the only difference
is that it waits for all entries to be returned to
the driver and for all frames the status has been
reported to mac80211.

We can easily split this task by calling rt2x00usb_kill_tx_queue,
sleep for a short period and invoke the TX status reporting
function. By adding the sleep() to the kill_entry we make sure
that even during shutdown we guarentee the entry has been killed when
the function returns. To make this work correctly the interrupt
handlers have to be updated to prevent checking for the RADIO_ENABLED
flag too early which prevents the ownership of the entry to be reset.
Additionally a check for the DEVICE_PRESENT flag is not required but
is nice to prevent race conditions when the device was unplugged.

Additionally rather then calling rt2x00usb_work_txdone() for
status reporting we let the driver perform the TX status reporting
first. If this is not sufficient then rt2x00usb_work_txdone() will
still be used to cleanup the mess.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The watchdog for rt2800usb triggers frequently causing all URB's
to be canceled often enough to interrupt the normal TX flow.
More research indicated that not the URB upload to the USB host
were hanging, but instead the TX status reports.

To correctly detect what is going on, we introduce Q_INDEX_DMA_DONE
which is an index counter between Q_INDEX_DONE and Q_INDEX and indicates
if the frame has been transfered to the device.

This also requires the rt2x00queue timeout functions to be updated
to differentiate between a DMA timeout (time between Q_INDEX and
Q_INDEX_DMA_DONE timeout) and a STATUS timeout (time between
Q_INDEX_DMA_DONE and Q_INDEX_DONE timeout)

All Q_INDEX_DMA_DONE code was taken from the RFC from
Helmut Schaa <helmut.schaa@googlemail.com> for the implementation
for watchdog for rt2800pci.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

All access to queue->entries through the Q_INDEX/Q_INDEX_DONE
variables must be done using spinlock protection. It is best
to manage this completely from rt2x00queue.c.

For safely looping through all entries in the queue, the function
rt2x00queue_for_each_entry is added which will walk from from a index
range in a safe manner.

This also fixes rt2x00usb which walked the entries list from
0 to length to kill each entry (killing entries must be done
from Q_INDEX_DONE to Q_INDEX to enforce TX status reporting to
occur in the correct order.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Cosmetic change, reduce indenting.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

write_tx_desc shouldn't pass a rt2x00dev and skb pointer,
instead it should use the same format as other TX frame
callback functions, which is passing the data_entry pointer
which contains all the information which is needed to work
on a TX frame.

Most callers of the kick_tx_queue and kill_tx_queue already
have the data_queue pointer, so rather then sending the QID
with the given function, when the driver requests a new
pointer to the data_queue, it is more efficient to just
send the data_queue pointer directly.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

At some points, some drivers can't report the full TX status
information. This can happen for the UNKNOWN state, or the
FAILURE state (in case the URB failed).
Add a wrapper function to simplify reporting the
empty TX information.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Move all TX and RX completion handling into a work structure,
which is handeled on the mac80211 workqueue. This simplifies
the code in rt2x00lib since it no longer needs to check if the
device is USB or PCI to decide which mac80211 function should be used.

In the watchdog some changes are needed since it can no longer rely
on the TX completion function to be run while looping through the
entries. (Both functions now work on the same workqueue, so this
would deadlock). So the watchdog now waits for the URB to return,
and handle the TX status report directly.

As a side-effect, the debugfs entry for the RX queue now correctly
displays the positions of the INDEX and INDEX_DONE counters. This
also implies that it is not possible to perform checks like queue_empty()
and queue_full() on the RX queue.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Implement watchdog monitoring for USB devices (PCI support can
be added later). This will determine if URBs being uploaded to
the hardware are actually returning. Both rt2500usb and rt2800usb
have shown that URBs being uploaded can remain hanging without
being released by the hardware.
By using this watchdog, a queue can be reset when this occurs.
For rt2800usb it has been tested that the connection is preserved
even though this interruption.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Now that the write_tx_data functions are merged, also merge the relevant
parts of the txdone handling into common code, rather than {usb,pci}
specific code.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Now that rt2x00pci_write_tx_data and rt2x00usb_write_tx_data are similar
we can merge them in a single function in rt2x00queue.c.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

There is no need to fill the TX URB this early, and moving it to the
rt2x00usb_kick_tx_entry function allows us to merge the PCI and USB
variants of the write_tx_data function.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We forgot to clear the SKBDESC_DESC_IN_SKB when the descriptor was removed
from the front of the skb.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>