PRI value is used as divider when DFS detector analyzes candidate
radar pulses.
If PRI deviation is big from its origin PRI, DFS detector could miss
valid radar reports since HW often misses detecting radar pulses and
causes long interval value of pulses.
For instance from practical results, if runtime PRI is calculated as
1431 for fixed PRI value of 1428 and delta timestamp logs 15719,
the modular remainder will be 1409 and the delta between the remainder
and runtime PRI is 22 that is bigger than PRI tolerance which is 16.
As a result this radar report will be ignored even though it's valid.
By using spec defined PRI for fixed PRI, we can correct this error.
Signed-off-by: Peter Oh <poh@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Some of radar types such as FCC radar type 5 require
to look up chirp in pulse to detect genuine radar and
it will prevent DFS channels from false radar detection.
Signed-off-by: Peter Oh <poh@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Move the DFS pattern detector code to the ath module so
the other Atheros drivers can make us of it. This makes
no functional changes.
Signed-off-by: Janusz Dziedzic <janusz.dziedzic@tieto.com>
Reviewed-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Peter Oh