Controls SCAN performed on mlan0.

[masakiyo]

We are trying to use mlan0 and uap0 simultaneously on 88W8987.

The problem is that when mlan0 do SCAN, uap0's throughput drops.

Previous question regarding this problem.

To solve this problem, it seemed necessary to have 88W9098, which has two MACs.

Therefore, we evaluated 88W9098(JODY-W374). But it turns out that this doesn't solve the problem either.

Even if there are two MACs, if mlan0 and uap0 use the same band, there seems to be no expected effect. (e.g. mlan0 and upa0 both use 2.4Ghz)

Therefore, we use the 88W8987, and we would like to be able to control SCAN by ourselves and adjust the timing and number of SCAN as we wish.

Currently, we are using NetworkManager and wpa_supplicant for mlan0.

NetworkManager 1.36.2

wpa_supplicant v2.10

driver_version = SD8987----16.92.21.p41.4-MM5X16391.p3-GPL-(FP92)
firmware_major_version=16.92.21

 Currently, SCAN is performed automatically as follows.

Before mlan0 connects to AP :

[ 29.898542] wlan: mlan0 START SCAN
[ 33.945094] wlan: SCAN COMPLETED: scanned AP count=22
[ 34.344170] wlan: mlan0 START SCAN
[ 40.790879] wlan: SCAN COMPLETED: scanned AP count=24
[ 41.703035] wlan: mlan0 START SCAN
[ 47.956884] wlan: SCAN COMPLETED: scanned AP count=24
[ 48.944270] wlan: mlan0 START SCAN
[ 55.229112] wlan: SCAN COMPLETED: scanned AP count=23
[ 59.018401] wlan: mlan0 START SCAN
[ 65.264105] wlan: SCAN COMPLETED: scanned AP count=21
[ 73.028675] wlan: mlan0 START SCAN
[ 79.292984] wlan: SCAN COMPLETED: scanned AP count=22
[ 93.028627] wlan: mlan0 START SCAN
[ 99.260906] wlan: SCAN COMPLETED: scanned AP count=20
[ 122.048303] wlan: mlan0 START SCAN
[ 128.342548] wlan: SCAN COMPLETED: scanned AP count=19
[ 165.028801] wlan: mlan0 START SCAN
[ 171.247640] wlan: SCAN COMPLETED: scanned AP count=18
[ 229.079834] wlan: mlan0 START SCAN
[ 235.349237] wlan: SCAN COMPLETED: scanned AP count=21
[ 324.103257] wlan: mlan0 START SCAN
[ 330.375692] wlan: SCAN COMPLETED: scanned AP count=21
[ 445.149469] wlan: mlan0 START SCAN
[ 451.411276] wlan: SCAN COMPLETED: scanned AP count=24
[ 451.950567] wlan: mlan0 START SCAN
[ 458.169671] wlan: SCAN COMPLETED: scanned AP count=25
[ 458.458457] wlan: mlan0 START SCAN
[ 464.723409] wlan: SCAN COMPLETED: scanned AP count=25
[ 465.030688] wlan: mlan0 START SCAN
[ 471.276801] wlan: SCAN COMPLETED: scanned AP count=24
[ 471.538967] wlan: mlan0 START SCAN
[ 477.828901] wlan: SCAN COMPLETED: scanned AP count=23
[ 481.028407] wlan: mlan0 START SCAN
[ 487.251035] wlan: SCAN COMPLETED: scanned AP count=22
[ 495.042905] wlan: mlan0 START SCAN
[ 501.279901] wlan: SCAN COMPLETED: scanned AP count=20

After mlan0 connects to AP :

SCAN does not occur because we have configured NetworkManager to disable roaming.

After mlan0 is disconnected from AP :

[ 7279.653487] wlan: HostMlme Disconnected: sub_type=12
[ 7279.773973] wlan: mlan0 START SCAN
[ 7286.313451] wlan: SCAN COMPLETED: scanned AP count=24
[ 7291.513454] wlan: mlan0 START SCAN
[ 7294.927802] IOCTL failed: 4b21050e id=0x10000, sub_id=0x10003 action=1, status_code=0x80000007
[ 7294.939812] wlan: SCAN COMPLETED: scanned AP count=25
[ 7295.225558] wlan: mlan0 START SCAN
[ 7301.502990] wlan: SCAN COMPLETED: scanned AP count=28
[ 7302.087992] wlan: mlan0 START SCAN
[ 7308.363479] wlan: SCAN COMPLETED: scanned AP count=27
[ 7308.660159] wlan: mlan0 START SCAN
[ 7314.917293] wlan: SCAN COMPLETED: scanned AP count=26
[ 7315.295276] wlan: mlan0 START SCAN
[ 7321.573122] wlan: SCAN COMPLETED: scanned AP count=26
[ 7321.890392] wlan: mlan0 START SCAN
[ 7328.126806] wlan: SCAN COMPLETED: scanned AP count=27
[ 7331.889978] wlan: mlan0 START SCAN
[ 7338.161638] wlan: SCAN COMPLETED: scanned AP count=28
[ 7345.885033] wlan: mlan0 START SCAN
[ 7352.190235] wlan: SCAN COMPLETED: scanned AP count=22
[ 7365.884532] wlan: mlan0 START SCAN
[ 7372.158653] wlan: SCAN COMPLETED: scanned AP count=23
[ 7394.893525] wlan: mlan0 START SCAN
[ 7401.136997] wlan: SCAN COMPLETED: scanned AP count=20
[ 7437.897817] wlan: mlan0 START SCAN
[ 7444.144690] wlan: SCAN COMPLETED: scanned AP count=22
[ 7501.916099] wlan: mlan0 START SCAN
[ 7508.144355] wlan: SCAN COMPLETED: scanned AP count=20
[ 7596.986665] wlan: mlan0 START SCAN
[ 7603.272977] wlan: SCAN COMPLETED: scanned AP count=23
[ 7603.864440] wlan: mlan0 START SCAN
[ 7610.135179] wlan: SCAN COMPLETED: scanned AP count=28
[ 7610.740446] wlan: mlan0 START SCAN
[ 7617.096800] wlan: SCAN COMPLETED: scanned AP count=27
[ 7617.409517] wlan: mlan0 START SCAN
[ 7623.650651] wlan: SCAN COMPLETED: scanned AP count=24

what I want to do

I would like to prevent SCAN from doing automatically after mlan0 is disconnected from the AP.
I want to control the timing of SCAN myself.

What methods are there?

[weidong_sun]

Dear @masakiyo ,

No special command to tell wpa_supplicant to stop scan. but you can refer to the following method:
1. Monitoring WiFi staus every some time( for example 2s) 
2. Controlling wpa_supplicant service to stop or start

--If WiFi is in disconnection mode, stop wpa_supplicant service using the command.
# systemctl stop wpa_supplicant.service
--when you need to another scaning , start wpa_supplicant service
# systemctl start wpa_supplicant.servic

Thanks!

Regards,

weidong

[weidong_sun]

Dear @masakiyo ,

For your questions:

>>We are trying to use mlan0 and uap0 simultaneously on 88W8987. The problem is that when mlan0 do SCAN, uap0's throughput drops.

88W9098 can indeed solve the problem.

After loading driver on linux platform, you can find these interfaces by default:

- MAC0:  mlan0/uap0/wfd0   (WIFI 6)  , it should work on 5G.

- MAC1: mmlan0/muap0/mwfd0 (WIFI 5), it should work on 2.4G

for your application, the combination should be one of them:

(1) mlan0 to be STA , and muap0 to be AP  (mlan0 5G & muap0 2.4G)

(2) uap0 to be AP, and mmlan0 to be STA (uap0 5G & mmlan0 2.4G)

[Note]

For STA connections , we recommend wpa_supplicant ver2.10 ; for micro AP, we recommend hostapd ver2.10.

Try it , please!

Regards,

weidong

[masakiyo]

@weidong_sun 

Thank you for your prompt reply.

Unfortunately, it is difficult to choose 5Ghz because our products are used outdoors in Japan and require long-distance communication via WiFi.

Therefore, STA and AP both use 2.4Ghz.

Sorry for not mentioning it in the previous message.