[OpenWrt-Devel] ath9k: fix dynack in IBSS mode

[Joe Ayers]

Lorenzo,  I have tested dynack on a (real distance apart) ~60km link
with some success.   This is the code change made:

--- a/drivers/net/wireless/ath/ath9k/dynack.c
+++ b/drivers/net/wireless/ath/ath9k/dynack.c
@@ -20,8 +20,9 @@

 #define COMPUTE_TO (5 * HZ)
 #define LATEACK_DELAY (10 * HZ)
-#define LATEACK_TO 256
-#define MAX_DELAY 300
+#define LATEACK_TO 1054
+/* AREDN max distance set to 150km */
+#define MAX_DELAY 1054
 #define EWMA_LEVEL 96
 #define EWMA_DIV 128

@@ -293,7 +294,8 @@
 void ath_dynack_node_init(struct ath_hw *ah, struct ath_node *an)
 {
  /* ackto = slottime + sifs + air delay */
- u32 ackto = 9 + 16 + 64;
+ /* AREDN starting point is 20km */
+ u32 ackto = 9 + 16 + 171;
  struct ath_dynack *da = &ah->dynack;

  an->ackto = ackto;
@@ -328,7 +330,8 @@
 void ath_dynack_reset(struct ath_hw *ah)
 {
  /* ackto = slottime + sifs + air delay */
- u32 ackto = 9 + 16 + 64;
+ /* AREDN starting point is 20km */
+ u32 ackto = 9 + 16 + 171;
  struct ath_dynack *da = &ah->dynack;

  da->lto = jiffies;

Notes:

1) The stations are showing ack_to between 525 up to 575 A.  When
static set at 60k distance, the timeout is set to 460 S.
2) significant performance improvement between these settings with
iperf3 and back to back runs with reboot in the middle:

run 1 @ static 60km:
[  5]   0.00-10.00  sec  7.31 MBytes  6.13 Mbits/sec    0             sender
[  5]   0.00-10.08  sec  7.16 MBytes  5.95 Mbits/sec                  receiver

run 2 @ static 60km:
[  5]   0.00-10.00  sec  5.88 MBytes  4.93 Mbits/sec    0             sender
[  5]   0.00-10.04  sec  5.77 MBytes  4.81 Mbits/sec                  receiver

run 1 and 2 @ auto distance -- goes up to ~575us with data flow,
floats back to ~525 otherwise:
[  5]   0.00-10.00  sec  20.0 MBytes  16.8 Mbits/sec    0             sender
[  5]   0.00-10.07  sec  19.8 MBytes  16.5 Mbits/sec                  receiver

[  5]   0.00-10.00  sec  21.4 MBytes  18.0 Mbits/sec    0             sender
[  5]   0.00-10.04  sec  21.2 MBytes  17.7 Mbits/sec                  receiver

3) running wpa_supplicant and psk2
4) running ibss on ch 176 with AREDN channels on top of 18.06.2
5) on one reboot, one of the stations stayed down at initial 196, then
bumped up to ~250 range and stayed there, link not functional.  Not
sure how to explain this value...

Question,  can this condition be true periodically while the link is
live or only at initial 802.11 adhoc link setup?:

                if (ieee80211_is_assoc_req(hdr->frame_control) ||
                    ieee80211_is_assoc_resp(hdr->frame_control) ||
                    ieee80211_is_auth(hdr->frame_control)) {

6)  Auto distance stayed at initial 196 when turning off encryption.

Any ideas of alternative options of packets to key off in late ack
situation?   running wpad-mini is ~500k file size and RAM consumer.
It would be beneficial to take wpa_supplicant out of the equation if
at all possible.

Joe

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