This patch changes the way tx status reports are handled by rt2800pci.
Previously rt2800pci would sometimes lose tx status reports as the
TX_STA_FIFO register is a fifo of 16 entries that can overflow in case
we don't read it often/fast enough. Since interrupts are disabled in the
device during the execution of the interrupt thread it happend sometimes
under high network and CPU load that processing took too long and a few
tx status reports were dropped by the hw.

To fix this issue the TX_STA_FIFO register is read directly in the
interrupt handler and stored in a kfifo which is large enough to hold
all status reports of all used tx queues.

To process the status reports a new tasklet txstatus_tasklet is used.
Using the already used interrupt thread is not possible since we don't
want to disable the TX_FIFO_STATUS interrupt while processing them and
it is not possible to schedule the interrupt thread multiple times for
execution. A tasklet instead can be scheduled multiple times which
allows to leave the TX_FIFO_STATUS interrupt enabled while a previously
scheduled tasklet is still executing.

In short: All other interrupts are handled in the interrupt thread as
before. Only the TX_FIFO_STATUS interrupt is partly handled in the
interrupt handler and finished in the according tasklet.

One drawback of this patch is that it duplicates some code from
rt2800lib. However, that can be cleaned up in the future once the
rt2800usb and rt2800pci tx status handling converge more.

Using this patch on a Ralink RT3052 embedded board gives me a reliable
wireless connection even under high CPU and network load. I've
transferred several gigabytes without any queue lockups.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We don't use all available interrupts in rt2800pci. Mask out all unused
interrupts to avoid waking up without having anything to do.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

According to the legacy drivers the AUTOWAKEUP_CFG
register must be reset to 0 before loading the firmware.

Instead of during rt2800{pci,usb}_write_firmware it
must actually be done in rt2800_load_firmware() before
resetting the WPDMA_GLO_CFG and PWR_PIN_CFG registers.
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 functions rt2800pci_enable_radio and rt2800usb_disable_radio are
almost equal and can be merged into rt2800lib. This reduces the number
of functions which must be exported from rt2800lib to the drivers at
the same time.

Also rt2800pci_disable_radio and rt2800usb_disable_radio are almost
equal and can be merged into rt2800lib in a similar fashion.
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 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>

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>

The TX_STA_FIFO register which is used for per-frame TX frame
status reporting is also valid on rt2800usb. We can move the
rt2800pci_txdone function into rt2800lib where it can also
be used by rt2800usb.

rt2800usb needs to overwrite the txdone work handler to
a different function.

Both rt2800usb as rt2800_txdone need to take into account
that IO failures can occur while uploading the URB, which
means that when obtaining the new entry the IO status must
be checked.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The only reason why the write_tx_data callback function
is needed inside the driver, is because the location of
the TXWI descriptor is different on PCI and USB hardware.
Except for the beacon, where the TXWI is always at the
start of the SKB buffer.

In both cases the drivers write_tx_data function only
wrap around the function rt2800_write_txwi. Move write_tx_data
completely into the rt2800lib library, and add a callback
function to obtain the TXWI pointer.
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 callback functions are gathered in rt2x00dev->ops except
for the callback functions which are used in rt2800lib to
acces rt2800pci/usb.

Move the priv pointer from rt2x00dev to rt2x00dev->ops and
rename it to drv to make it obvious that it is the driver callback
structure.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Large parts of the firmware initialization are shared
between rt2800pci and rt2800usb. Move this code into
rt2800lib.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Using the set_tim callback without managing the DTIM count and the
broad- and multicast buffering in hw, fw or the driver results in wrong
DTIM count values being sent out in beacons. Since all PCI drivers
fetch new beacons periodically and hence get an updated TIM we can just
remove the set_tim callback from these.

The rt2x00 USB drivers don't update the beacon periodically and thus
rely on the set_tim callback to get a correct TIM for beacon
transmission. USB devices still suffer from the DTIM count being wrong
under some circumstances but removing the set_tim callback from these
would cause more harm then good.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Use separate mac80211_ops for rt2800pci and rt2800usb in preparation
for further fixes. This shouldn't introduce functional changes.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Updating the beacon on pre tbtt instead of beacondone allows much lower
latency in regard to TIM updates. Hence, use the pre tbtt interrupt for
updating the beacon in rt2800pci (older devices don't provide a pre tbtt
interrupt).

Also, add a new driver flag to indicate if a driver has pre tbtt support
or not and implement the according behavior in rt2x00lib.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Use threaded interrupts for all rt2x00 PCI devices.

This has several generic advantages:
- Reduce the time we spend in hard irq context
- Use non-atmic mac80211 functions for rx/tx

Furthermore implementing broad- and multicast buffering will be
much easier in process context while maintaining low latency and
updating the beacon just before transmission (pre tbtt interrupt)
can also be done in process context.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Rename CONFIG_DISABLE_LINK_TUNING to DRIVER_SUPPORT_LINK_TUNING
Link tuning support is not only based on EEPROM decisions, but
also if the device actually supports it.

Currently only rt2500usb doesn't support link tuning because
of hardware problems. But rt2800usb is also suspected of having
problems with link tuning.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

The RSSI values in the RXWI descriptor aren't true RSSI
values. Instead they are more like the AGC values similar
to rt61pci. And as such, it needs the same conversion
before it can be passed to rt2x00lib/mac80211.

This requires the struct queue_entry to be passed to
rt2800_process_rxwi rather then the skb structure which
is contained in the queue_entry. This is required to
obtain the lna_gain information from the rt2x00_dev structure.

This fixes connection problems when using wpa_supplicant
which would try to connect to the worst AP's rather then the
best ones.
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

rt2800pci didn't update the beacon template after each beacon interval,
resulting in the DTIM count being incorrect (if DTIM period > 1). Fix this
by calling rt2x00lib_beacondone after the current beacon was sent out.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

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>

Align with the way PCI devices are handled, even though it is not
strictly necessary.
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 the {usb,pci} specific write_tx_data functions are no longer
present we can rename the write_tx_datadesc callback function back to
its old name.
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 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>

Hardware cryptography seems to be working
on a 11G network with WPA/WPA2 cryptography
enabled. WEP still needs to be tested...
Signed-of-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Currently rt2800pci will read TX_STA_FIFO until the previously read value
matches the current value. However, it is obvious that TX_STA_FIFO only
contains values that can easily be the same for multiple consecutive frames
(especially when communicating with only one other STA). Hence, we often
ended up with reading only the first entry and ignoring the rest.

One result was that when the TX_STA_FIFO contained multiple entires, only
the first one was read and properly handled while the others remained in the
tx queue.

Thus, drop this check but introduce a maximum number of reads. All legacy
drivers use the size of the tx ring as limit but state that the TX_STA_FIFO
has only 16 entries. So, let's just stick with the tx ring size for now.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Acked-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>

TXDONE_FALLBACK expresses that fallback rates were used for retries. Hence,
it only makes sense to set the flag if retries > 0.
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Acked-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>

Latest versions of the Ralink rt2800 family drivers use 0 as the token value,
not 0xff.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>

This prevents us having common code depend on PCI or USB specific code.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>

The beacon writing functions of rt2800pci and rt2800usb are now identical.
Move them to rt2800lib to only have one central function.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>

Instead of fiddling with the skb->data pointer and thereby risking
out of bounds accesses, properly reserve the space needed in an
skb for descriptors.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Acked-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>

For rt2800 reverse the calling order of rt2x00pci_write_data and
rt2800pci_write_data. Currently rt2800pci_write_data calls rt2x00pci_write_data
as there can be only 1 driver callback function specified by the driver.
Reverse this calling order by introducing a new driver callback function,
called write_tx_datadesc, which is called from the bus-specific write_tx_data
functions.
Preparation for futher cleanups in the skb data handling of rt2x00.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>

Not all the devices require a TX descriptor to be written (i.e. rt2800
device don't require them). Push down the creation of the TX descriptor
to the device drivers so that they can decide for themselves whether
a TX descriptor is to be created.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NIvo van Doorn <IvDoorn@gmail.com>

The handling of tx descriptors for beacons can be simplified by updating
write_tx_desc implementations of each driver to write directly to the
queue entry descriptor instead of to a provided memory area.
This is also a preparation for further clean ups where descriptors are
properly reserved in the skb instead of fiddling with the skb data
pointer.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Acked-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

According to the Ralink vendor driver for rt2800 we don't need a full
TXD for a beacon but just a TXWI in front of the actual beacon.
Fix the rt2800pci and rt2800usb beaconing code accordingly.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Acked-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

Preparation to fix rt2800 beaconing.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Acked-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

All of the driver's kick_tx_queue callback functions treat the TX queue
for beacons in a special manner.
Clean this up by integrating the kicking of the beacon queue into the
write_beacon callback function, and let the generic code no longer call
the kick_tx_queue callback function when updating the beacon.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Acked-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

RXWI processing is exactly the same for rt2800pci and rt2800usb, so
make it common code.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Acked-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

TXWI writing is exactly the same for rt2800pci and rt2800usb, so
make it common code.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Acked-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

We should simply follow what the hardware told us it has done.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Acked-by: NIvo van Doorn <IvDoorn@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

rt2800 devices use a different enumeration to specify what IFS values should
be used on frame transmission compared to the other rt2x00 devices. Hence,
create a new enum called txop that contains the valid values.

Furthermore use the appropriate txop values as found in the ralink drivers:
- TXOP_BACKOFF for management frames
- TXOP_SIFS for subsequent fragments in a burst
- TXOP_HTTXOP for all data frames
Signed-off-by: NHelmut Schaa <helmut.schaa@googlemail.com>
Acked-by: NIvo van Doorn <IvDoorn@gmail.com>
Acked-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

And use it consistently in the chipset drivers.
Preparation for further clean ups.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>