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Bruno Randolf a écrit :
| From: Bruno Randolf <[EMAIL PROTECTED]>
|
| atheros hardware seems to have a problem with the rx timestamp of IBSS
beacons.
| unfortunately this is the case where rx timestamps count most in order to
| correctly merge IBSS. specifically it looks like the rx timestamp is
wrong for
| *some* IBSS beacons which have the same BSSID and which cause the HW
to adapt
| the TSF of the beacon. in that case ath5k_extend_tsf() will assume a
rs_tstamp
| overflow and give us a timestamp too far in the past which will cause
mac80211
| to merge IBSS (which is not necessary since the BSSID already
matches). but in
| this case we know that the HW must have synced to the beacons TSF and can
| adjust mactime accordingly - it can't be earlier than the beacon's
timestamp.
|
| also rename the function to ath5k_check_ibss_tsf() since "hw merge" is
an odd
| term.

The problem is pretty simple:

* rs_tstamp is the lowest bits of the TSF when we received the packet
(don't know if it's sample at the beginning or the end of the packet)

* on some beacons, hardware TSF is updated

* later on, the software driver (be it ath5k or madwifi) tries to
combine the rs_tstamp and the new hardware TSF, which is obviously wrong!

Regards,
Benoit
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