Forums - Monitor Mode Frame "Clearing"

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Monitor Mode Frame "Clearing"
Join Date: 17 Nov 20
Posts: 28
Posted: Thu, 2022-03-10 05:07


Currently running Linux, QCA9377-7, USB.

I have a monitor mode / sniffer mode question. This might not be a driver interface question, it might be a linux command interface question, not sure, but please bear with me.

Loading the driver with con_mode=4, open it as a socket, and am getting data really well. Use setMonChan to go to the channels I want, works great.

But, for a bit of time, I am still reading from the socket the previous channel, and eventually I get to the new channel's socket.


iwpriv wlan0 setMonChan 44 0

read the socket, see quite a few APs and Stations on channel 44.

about 5 seconds later, I switch to say channel 1

For a period of time (sometimes a second or so, sometimes almost immediately) I still see channel 44 frames.

I am currently weeding out channels that aren't the one I'm currently scanning, but, was wondering, is there a command I can give to have the driver or QCA or ??? clean out all frames it has? Without causing it to go take more than a few ms to start having the new channels frames ready?

If not, I can continue to weed them out, but would be nice to be able to use a "flush frames" after I set a channel before I start reading, just to keep things cleaner in my code. 

Thanks in advance,


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ddeepakk Moderator
Join Date: 27 Jun 17
Posts: 140
Posted: Thu, 2022-05-05 03:26

Hi John,

Thank you for bringing this to our notice.
It seems the queues aren't flushed on channel change, leading to this issue.
I'll inform the internal team to take a look at it and get back to you on their feedback.



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