Allow the device to give the driver RX data with reorder information.
When that is done, the device will indicate the driver if a packet has
to be held in a (sorted) queue. It will also tell the driver when held
packets have to be released to the OS.
This is done to improve the WiMAX-protocol level retransmission
support when missing frames are detected.
The code docs provide details about the implementation.
In general, this just hooks into the RX path in rx.c; if a packet with
the reorder bit in the RX header is detected, the reorder information
in the header is extracted and one of the four main reorder operations
are executed. In one case (queue) no packet will be delivered to the
networking stack, just queued, whereas in the others (reset, update_ws
and queue_update_ws), queued packet might be delivered depending on
the window start for the specific queue.
The modifications to files other than rx.c are:
- control.c: during device initialization, enable reordering support
if the rx_reorder_disabled module parameter is not enabled
- driver.c: expose a rx_reorder_disable module parameter and call
i2400m_rx_setup/release() to initialize/shutdown RX reorder
support.
- i2400m.h: introduce members in 'struct i2400m' needed for
implementing reorder support.
- linux/i2400m.h: introduce TLVs, commands and constant definitions
related to RX reorder
Last but not least, the rx reorder code includes an small circular log
where the last N reorder operations are recorded to be displayed in
case of inconsistency. Otherwise diagnosing issues would be almost
impossible.
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Newer i2400m firmwares (>= v1.4) extend the data RX protocol so that
each packet has a 16 byte header. This header is mainly used to
implement host reordeing (which is addressed in later commits).
However, this header also allows us to overwrite it (once data has
been extracted) with an Ethernet header and deliver to the networking
stack without having to reallocate the skb (as it happened in fw <=
v1.3) to make room for it.
- control.c: indicate the device [dev_initialize()] that the driver
wants to use the extended data RX protocol. Also involves adding the
definition of the needed data types in include/linux/wimax/i2400m.h.
- rx.c: handle the new payload type for the extended RX data
protocol. Prepares the skb for delivery to
netdev.c:i2400m_net_erx().
- netdev.c: Introduce i2400m_net_erx() that adds the fake ethernet
address to a prepared skb and delivers it to the networking
stack.
- cleanup: in most instances in rx.c, the variable 'single' was
renamed to 'single_last' for it better conveys its meaning.
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove some pointless conditionals before kfree_skb().
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Handling of TX/RX data to/from the i2400m device (IP packets, control
and diagnostics). On RX, this parses the received read transaction
from the device, breaks it in chunks and passes it to the
corresponding subsystems (network and control).
Transmission to the device is done through a software FIFO, as
data/control frames can be coalesced (while the device is reading the
previous tx transaction, others accumulate). A FIFO is used because at
the end it is resource-cheaper that scatter/gather over USB. As well,
most traffic is going to be download (vs upload).
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
