[rt2x00-users] [RFC/RFT 0/5] rt2x00: rt2800usb: rework tx path

[Stanislaw Gruszka]

This patch set try to make tx better on rt2800usb driver. Especially
regarding matching tx statuses with sent frames. There should be
observable performance gain (especially on bad radio conditions) and
cpu usage increase. For example, on my environment, command 

perf stat -e cycles -a -r 10 scp -B BIG.file stasiu at 192.168.2.102:~/

gave me following results

Before:

 Performance counter stats for 'scp -B BIG.file stasiu at 192.168.2.102:~/' (10 runs):

    34,301,020,450 cycles                    #    0.000 GHz                      ( +-  1.37% )

      17.389285786 seconds time elapsed                                          ( +-  2.55% )

After:

 Performance counter stats for 'scp -B BIG.file stasiu at 192.168.2.102:~/' (10 runs):

    20,167,124,795 cycles                    #    0.000 GHz                      ( +-  0.24% )

      13.965509823 seconds time elapsed                                          ( +-  0.63% )

What is about 20% better throughput and about 40% better cpu usage.