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clarification on beacon reception

Vijayasarathy Shastri
Intellectual 1840 points
Other Parts Discussed in Thread: WL1271

Hi,

I want clarification about  beacon on wl1271/1273 device

One of the GPIO pins from the wireless card (wlan_irq) = notification of reception of a packet of any kind.

I have examined the WL1271 code relating to beacons and the CPU decides if a received packet is a beacon by analyzing it. 


-I would like  to know if the WL1271 card identifies a received packet as a beacon corresponding to the SSID of the wireless card (i.e. NOT just any beacon packet)
- if it does, in the WL1271 card is there a beacon counter (increments when a beacon is detected ?) or a beacon timer (time since the last beacon reception ?) or a flag (indicating that the last packet received was a beacon ?).


Note: the CPU repetitively forwards a beacon filter table to the WL1271 card that causes many of the beacon packets not to be forwarded to the CPU (to reduce the CPU's work). Therefore, as the WL1271 driver is presently configured, it is useless to analyze beacon packets as they are forwarded to the CPU (> 50% are missing, say). The flip side of this dilemma is the opportunity to examine some register in the WL1271 card for beacon packet info (however, such a register might contain beacon info on all SSIDs).

 

 

Please advise. Thanks in advance.

 

Best Regards,

 

N.Vijayasarathy

  • 0
    TI__Genius 9240 points

    Hi Vijayasarathy,

     

    As for beacon reception, it depends of the Driver state. For example when the driver performs scan then it send a filter to the firmware that enables receiving beacons and probe responses from all SSID since the intention is to discover the Access point around regardless of their SSID. And then once the Station had connected to a specific AP then the firmware will start receiving beacons from the Access point it is connected to however will not receive beacons from different SSID.

     

    In addition the firmware receives the beacons however in order to reduce the events were the firmware wakes the Host then in case there is nothing interesting in the beacon then the firmware will not send it to the Driver, that is the case were for example the Beacon had no information like pending Data in the AP for the specific Station or in case there are no broadcast frames. In addition if there is no change in one of the beacon field.  All that can be configured.

     

    Regards,

    Eyal