diff mbox

[v2] ath: use PRI value given by spec for fixed PRI

Message ID f9db7f54d12e2589bcbb39215049d51a762d5d75.1441731619.git.poh@qca.qualcomm.com (mailing list archive)
State Changes Requested
Headers show

Commit Message

Peter Oh Sept. 8, 2015, 5:04 p.m. UTC
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>
---
 drivers/net/wireless/ath/dfs_pattern_detector.c | 6 ------
 drivers/net/wireless/ath/dfs_pattern_detector.h | 5 +++++
 drivers/net/wireless/ath/dfs_pri_detector.c     | 6 +++++-
 3 files changed, 10 insertions(+), 7 deletions(-)

Comments

Kalle Valo Sept. 9, 2015, 9:55 a.m. UTC | #1
Peter Oh <poh@qca.qualcomm.com> writes:

> 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>

A changelog would be good to have. What changed in v2?
diff mbox

Patch

diff --git a/drivers/net/wireless/ath/dfs_pattern_detector.c b/drivers/net/wireless/ath/dfs_pattern_detector.c
index 656ce42..0cc89fd 100644
--- a/drivers/net/wireless/ath/dfs_pattern_detector.c
+++ b/drivers/net/wireless/ath/dfs_pattern_detector.c
@@ -21,12 +21,6 @@ 
 #include "dfs_pri_detector.h"
 #include "ath.h"
 
-/*
- * tolerated deviation of radar time stamp in usecs on both sides
- * TODO: this might need to be HW-dependent
- */
-#define PRI_TOLERANCE	16
-
 /**
  * struct radar_types - contains array of patterns defined for one DFS domain
  * @domain: DFS regulatory domain
diff --git a/drivers/net/wireless/ath/dfs_pattern_detector.h b/drivers/net/wireless/ath/dfs_pattern_detector.h
index 25a43d6..92be353 100644
--- a/drivers/net/wireless/ath/dfs_pattern_detector.h
+++ b/drivers/net/wireless/ath/dfs_pattern_detector.h
@@ -21,6 +21,11 @@ 
 #include <linux/list.h>
 #include <linux/nl80211.h>
 
+/* tolerated deviation of radar time stamp in usecs on both sides
+ * TODO: this might need to be HW-dependent
+ */
+#define PRI_TOLERANCE	16
+
 /**
  * struct ath_dfs_pool_stats - DFS Statistics for global pools
  */
diff --git a/drivers/net/wireless/ath/dfs_pri_detector.c b/drivers/net/wireless/ath/dfs_pri_detector.c
index cc5c592..05b0464 100644
--- a/drivers/net/wireless/ath/dfs_pri_detector.c
+++ b/drivers/net/wireless/ath/dfs_pri_detector.c
@@ -25,6 +25,9 @@  struct ath_dfs_pool_stats global_dfs_pool_stats = {};
 
 #define DFS_POOL_STAT_INC(c) (global_dfs_pool_stats.c++)
 #define DFS_POOL_STAT_DEC(c) (global_dfs_pool_stats.c--)
+#define GET_PRI_TO_USE(MIN, MAX, RUNTIME) \
+	(MIN + PRI_TOLERANCE == MAX - PRI_TOLERANCE ? \
+	MIN + PRI_TOLERANCE : RUNTIME)
 
 /**
  * struct pulse_elem - elements in pulse queue
@@ -243,7 +246,8 @@  static bool pseq_handler_create_sequences(struct pri_detector *pde,
 		ps.count_falses = 0;
 		ps.first_ts = p->ts;
 		ps.last_ts = ts;
-		ps.pri = ts - p->ts;
+		ps.pri = GET_PRI_TO_USE(pde->rs->pri_min,
+			pde->rs->pri_max, ts - p->ts);
 		ps.dur = ps.pri * (pde->rs->ppb - 1)
 				+ 2 * pde->rs->max_pri_tolerance;