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

[Lorenzo Bianconi]

>
> bump.

Hi Joe,

sorry for the delay

>
> On Mon, Mar 18, 2019 at 10:59 PM Joe Ayers <joe at ayerscasa.com> wrote:
>>
>> 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:
>>

could you please try to attached patch? The max distance the hw can
support depends of channel width:
e.g @20MHz (HT20, 5GHz)

max distance is ~ 61Km

@Koen: do you have any chance to test the attached patch in your
environment? Thx

>> 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)) {
>>

I do not think so since AFAIK auth frames are sent just during ibss join

>> 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.
>>

What is mandatory are unicast frames during joining phase, maybe you can
develop an userspace daemon for this purpose

>> Joe

Regards,
Lorenzo
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