2021-10-19 21:52:49

by James Prestwood

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Subject: Bug - brcmfmac STA fails to channel switch

Hi,

I've noticed some funny behavior on brcmfmac STA's when issuing a
channel switch to hostapd.

First, I tried this on a really old brcmfmac card. This got stuck in a
loop: DEL_STATION, NEW_STATION, TX_STATUS, ROAM (repeat). I chalked it
up to the card being old and unsupported.

I then tried on a rpi3 and would get disconnected soon after issuing
the channel switch to hostapd. No other events came, just a disconnect.

In one case I issued a channel switch and saw hostapd responding to SA
Query requests about once a second. But no other events came on the STA
side. The card/FW seemed to be stuck in a loop sending SA Queries once
per second but never issued a CHANNEL_SWITCH or ROAM event. This went
on for about 5 minutes before I stopped the tests.

If channel switching is not supported I think the disconnect behavior I
saw is about all that can be done. As for the SA query loop, that seems
like a bug to me.

Thanks,
James