Took a little longer to freeze -- 2 days this time.
Jun 17 17:41:59 BUFFALO daemon.info hostapd: ath0: STA 00:11:xx:xx:xx:3a WPA: group key handshake completed (RSN)
Jun 17 17:41:59 BUFFALO daemon.info hostapd: ath0: STA 00:1e:xx:xx:xx:28 WPA: group key handshake completed (RSN)
Jun 17 18:41:59 BUFFALO daemon.info hostapd: ath0: STA 00:11:xx:xx:xx:3a WPA: group key handshake completed (RSN)
Jun 17 18:41:59 BUFFALO daemon.info hostapd: ath0: STA 00:1e:xx:xx:xx:28 WPA: group key handshake completed (RSN)
Jun 17 19:38:38 BUFFALO kern.warn kernel: [212221.660000] Sending cwmmode action frame to ff:ff:ff:ff:ff:ff
Jun 17 19:42:02 BUFFALO daemon.info hostapd: ath0: STA 00:11:xx:xx:xx:3a IEEE 802.11: deauthenticated due to local deauth request
Jun 17 19:42:02 BUFFALO daemon.info hostapd: ath0: STA 00:1e:xx:xx:xx:28 IEEE 802.11: deauthenticated due to local deauth request
Jun 17 19:42:02 BUFFALO daemon.info hostapd: ath0: STA 00:11:xx:xx:xx:3a IEEE 802.11: disassociated
Jun 17 19:42:02 BUFFALO daemon.info hostapd: ath0: STA 00:1e:xx:xx:xx:28 IEEE 802.11: disassociated
The bold line represents the time of the freeze. All wireless clients disconnected, none could reconnect, router still works for wired clients.
During the freeze inSSIDer was showing the router with extremely low barely detectable power output, and only occasional blips at that. Neighbors routers over 500ft away showed higher power than this one inside the house.
Also during the freeze, the wireless status page would show slowly increasing transmitted packets, as if router thinks it is still transmitting SSID.
iwlist ath0 txpower showed 19dBm as did the router's wireless status page, but it was definitely not spewing that much power.
iwconfig ath0 txpower 22 had no effect and subsequent iwlist txpower still showed 19, but inSSIDer showed it was almost nothing.
Now here comes the fun part. I tried this command I found recently in dd-wrt forums:
80211n_wlanconfig ath0 set_txpowercap 00:xx:xx:xx:xx:AC 22
And magically the power came back up (iwlist txpower showed new 22dBm value) and all the clients instantly began reconnected after being disconnected for over 12 hours. And inSSIDer showed a solid healthy signal coming from the router again.
Here is what the log shows just before and after the reconnect:
Jun 18 12:20:36 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: associated
Jun 18 12:20:37 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: associated
Jun 18 12:20:38 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: deauthenticated due to local deauth request
Jun 18 12:20:38 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: disassociated
Jun 18 12:20:42 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: associated
Jun 18 12:20:45 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: deauthenticated due to local deauth request
Jun 18 12:20:45 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: disassociated
Jun 18 12:22:07 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: associated
Jun 18 12:22:10 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: deauthenticated due to local deauth request
Jun 18 12:22:10 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: disassociated
Jun 18 12:23:16 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: associated
Jun 18 12:23:19 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: deauthenticated due to local deauth request
Jun 18 12:23:19 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: disassociated
Jun 18 12:24:32 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: associated
Jun 18 12:24:35 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: deauthenticated due to local deauth request
Jun 18 12:24:35 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: disassociated
Jun 18 12:25:14 BUFFALO kern.warn kernel: [272617.470000] ic->ic_cwm.cw_width :1, ic->ic_cwm.cw_extoffset: 0
Jun 18 12:25:15 BUFFALO daemon.info hostapd: ath0: STA 00:xx:xx:xx:xx:28 IEEE 802.11: associated
Jun 18 12:25:15 BUFFALO daemon.info hostapd: ath0: STA 00:xx:xx:xx:xx:28 RADIUS: starting accounting session 00000003-0000001A
Jun 18 12:25:15 BUFFALO daemon.info hostapd: ath0: STA 00:xx:xx:xx:xx:28 WPA: pairwise key handshake completed (RSN)
Jun 18 12:25:59 BUFFALO daemon.info hostapd: ath0: STA 00:xx:xx:xx:xx:3a IEEE 802.11: associated
Jun 18 12:25:59 BUFFALO daemon.info hostapd: ath0: STA 00:xx:xx:xx:xx:3a RADIUS: starting accounting session 00000003-0000001B
Jun 18 12:25:59 BUFFALO daemon.info hostapd: ath0: STA 00:xx:xx:xx:xx:3a WPA: pairwise key handshake completed (RSN)
Jun 18 12:26:35 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 IEEE 802.11: associated
Jun 18 12:26:35 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 RADIUS: starting accounting session 00000003-0000001C
Jun 18 12:26:35 BUFFALO daemon.info hostapd: ath0: STA 4c:xx:xx:xx:xx:92 WPA: pairwise key handshake completed (RSN)
Jun 18 12:26:38 BUFFALO kern.warn kernel: [272701.490000] Sending cwmmode action frame to ff:ff:ff:ff:ff:ff
So it looks like the wireless freeze is related somehow to the real txpower being cut to near nothing, even though iwlist txpower and wireless status page still showed normal power output. The new set_txpowercap command seemed to work where ifconfig txpower did not, and restored wireless connectivity. At least that is what it looked like from my perspective.
I sure hope this can get fixed soon, whether it is a dd-wrt native problem or a hardware problem that dd-wrt needs to detect and workaround.
Oh, and while on the subject of set_txpowercap -- even after setting the value to 22dBm this way, it eventually falls back to 19dBm. No idea why the set_txpowercap value is not sticky. Perhaps that is related to the same problem. Also, no idea why setting the GUI transmit power does not seem to use the set_txpowercap mechanism which seems to have a definite effect while iwconfig txpower does not.
Please let me know if you'd like me to collect any additional info from subsequent wireless freezes.