Hi, We are facing a lot of wireless related problems for one of products deployed at customer place . The customer is reporting frequent freeze/crash of the system. We have never been able to reproduce this problem in our lab, but in a wireless environment with many Access points, the crash does occur quite frequently when the system moves from one AP to another Our product’s Linux kernel is based on 2.6.2 and we are using compat-3.3.n drivers for PCI based ath9k card Having investigated the logs, we have observed that the crash is mainly occurring due to mac80211 dynamic power save module. Following information is recorded in log every time prior to crash/system freeze. --------------------------------------------------------------------------- ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- ---- un 1 17:18:46 test kernel: [10176.378049] wlan0: moving STA 00:22:55:f2:ff:09 to state 1 Jun 1 17:18:46 test kernel: [10176.378052] wlan0: moving STA 00:22:55:f2:ff:09 to state 0 Jun 1 17:18:46 test kernel: [10176.388077] wlan0: associate with 00:22:55:f3:34:69 (try 1) Jun 1 17:18:46 test kernel: [10176.392344] wlan0: RX ReassocResp from 00:22:55:f3:34:69 (capab=0x431 status=0 aid=129) Jun 1 17:18:46 test kernel: [10176.392348] wlan0: associated Jun 1 17:18:46 test kernel: [10176.392352] wlan0: moving STA 00:22:55:f3:34:69 to state 1 Jun 1 17:18:46 test kernel: [10176.392354] wlan0: moving STA 00:22:55:f3:34:69 to state 2 Jun 1 17:18:46 test kernel: [10176.410656] wlan0: moving STA 00:22:55:f3:34:69 to state 3 Jun 1 17:19:48 test kernel: [10238.735122] wlan0: authenticate with 00:22:55:44:62:76 (try 1) Jun 1 17:19:48 test kernel: [10238.834021] ------------[ cut here ]-------- ---- Jun 1 17:19:48 test kernel: [10238.834060] WARNING: at /usr/local/src/compat-wireless-3.3-2-n/net/mac80211/tx.c:767 invoke_tx_handlers+0xb20/0x13c0 [mac80211]() Jun 1 17:19:48 test kernel: [10238.834064] Hardware name: OEM-A1901-00 Jun 1 17:19:48 test kernel: [10238.834145] Call Trace: Jun 1 17:19:48 test kernel: [10238.834160] [<ffffffff81005ca9>] dump_trace+0x79/0x340 Jun 1 17:19:48 test kernel: [10238.834168] [<ffffffff814a0bb4>] dump_stack+0x69/0x6f Jun 1 17:19:48 test kernel: [10238.834176] [<ffffffff81051993>] warn_slowpath_common+0x73/0xb0 Jun 1 17:19:48 test kernel: [10238.834196] [<ffffffffa0412640>] invoke_tx_handlers+0xb20/0x13c0 [mac80211] Jun 1 17:19:48 test kernel: [10238.834248] [<ffffffffa04130b7>] ieee80211_tx+0x87/0x130 [mac80211] Jun 1 17:19:48 test kernel: [10238.834302] [<ffffffffa041320c>] ieee80211_xmit+0xac/0x150 [mac80211] Jun 1 17:19:48 test kernel: [10238.834347] [<ffffffffa0414477>] ieee80211_tx_skb_tid+0x57/0x70 [mac80211] Jun 1 17:19:48 test kernel: [10238.834395] [<ffffffffa03fea90>] ieee80211_dynamic_ps_enable_work+0x2b0/0x4c0 [mac80211] Jun 1 17:19:48 test kernel: [10238.834416] [<ffffffff8106e010>] run_workqueue+0xb0/0x1d0 Jun 1 17:19:48 test kernel: [10238.834422] [<ffffffff8106e1cb>] worker_thread+0x9b/0x100 Jun 1 17:19:48 test kernel: [10238.834429] [<ffffffff8107167e>] kthread+0x8e/0xa0 Jun 1 17:19:48 test kernel: [10238.834435] [<ffffffff81003df4>] kernel_thread_helper+0x4/0x10 Jun 1 17:19:48 test kernel: [10238.834440] ---[ end trace 5490dac9b02f8a16 ]--- Jun 1 17:19:48 test kernel: [10238.834444] ------------[ cut here ]-------- ---- Jun 1 17:19:48 test kernel: [10238.834462] WARNING: at /usr/local/src/compat-wireless-3.3-2-n/net/mac80211/tx.c:55 invoke_tx_handlers+0x1325/0x13c0 [mac80211]() Jun 1 17:19:48 test kernel: [10238.834572] Call Trace: Jun 1 17:19:48 test kernel: [10238.834579] [<ffffffff81005ca9>] dump_trace+0x79/0x340 Jun 1 17:19:48 test kernel: [10238.834585] [<ffffffff814a0bb4>] dump_stack+0x69/0x6f Jun 1 17:19:48 test kernel: [10238.834591] [<ffffffff81051993>] warn_slowpath_common+0x73/0xb0 Jun 1 17:19:48 test kernel: [10238.834611] [<ffffffffa0412e45>] invoke_tx_handlers+0x1325/0x13c0 [mac80211] Jun 1 17:19:48 test kernel: [10238.834657] [<ffffffffa04130b7>] ieee80211_tx+0x87/0x130 [mac80211] Jun 1 17:19:48 test kernel: [10238.834701] [<ffffffffa041320c>] ieee80211_xmit+0xac/0x150 [mac80211] Jun 1 17:19:48 test kernel: [10238.834746] [<ffffffffa0414477>] ieee80211_tx_skb_tid+0x57/0x70 [mac80211] Jun 1 17:19:48 test kernel: [10238.834790] [<ffffffffa03fea90>] ieee80211_dynamic_ps_enable_work+0x2b0/0x4c0 [mac80211] Jun 1 17:19:48 test kernel: [10238.834809] [<ffffffff8106e010>] run_workqueue+0xb0/0x1d0 Jun 1 17:19:48 test kernel: [10238.834814] [<ffffffff8106e1cb>] worker_thread+0x9b/0x100 Jun 1 17:19:48 test kernel: [10238.834820] [<ffffffff8107167e>] kthread+0x8e/0xa0 Jun 1 17:19:48 test kernel: [10238.834825] [<ffffffff81003df4>] kernel_thread_helper+0x4/0x10 Jun 1 17:19:48 test kernel: [10238.834829] ---[ end trace 5490dac9b02f8a17 ]--- Jun 1 17:19:49 test kernel: [10239.431272] wlan0: authenticate with 00:22:55:44:62:76 (try 2) Jun 1 17:19:49 test kernel: [10239.631216] wlan0: authenticate with 00:22:55:44:62:76 (try 3) Jun 1 17:19:49 test kernel: [10239.831018] wlan0: authentication with 00:22:55:44:62:76 timed out Jun 1 17:19:49 test kernel: [10239.841324] ath: Failed to stop TX DMA, queues=0x001! Jun 1 17:19:49 test kernel: [10239.848357] ------------[ cut here ]-------- ---- Jun 1 17:19:49 test kernel: [10239.848375] WARNING: at /usr/local/src/compat-wireless-3.3-2- n/drivers/net/wireless/ath/ath9k/rc.c:794 ath_rc_get_highest_rix+0x1f6/0x210 [ath9k]() Jun 1 17:19:49 test kernel: [10239.848459] Call Trace: Jun 1 17:19:49 test kernel: [10239.848474] [<ffffffff81005ca9>] dump_trace+0x79/0x340 Jun 1 17:19:49 test kernel: [10239.848482] [<ffffffff814a0bb4>] dump_stack+0x69/0x6f Jun 1 17:19:49 test kernel: [10239.848490] [<ffffffff81051993>] warn_slowpath_common+0x73/0xb0 Jun 1 17:19:49 test kernel: [10239.848498] [<ffffffffa04e4fc6>] ath_rc_get_highest_rix+0x1f6/0x210 [ath9k] Jun 1 17:19:49 test kernel: [10239.848524] [<ffffffffa04e5068>] ath_get_rate+0x88/0x470 [ath9k] Jun 1 17:19:49 test kernel: [10239.848561] [<ffffffffa040646e>] rate_control_get_rate+0x8e/0x150 [mac80211] Jun 1 17:19:49 test kernel: [10239.848599] [<ffffffffa0412508>] invoke_tx_handlers+0x9e8/0x13c0 [mac80211] Jun 1 17:19:49 test kernel: [10239.848645] [<ffffffffa04130b7>] ieee80211_tx+0x87/0x130 [mac80211] Jun 1 17:19:49 test kernel: [10239.848689] [<ffffffffa041320c>] ieee80211_xmit+0xac/0x150 [mac80211] Jun 1 17:19:49 test kernel: [10239.848733] [<ffffffffa0414477>] ieee80211_tx_skb_tid+0x57/0x70 [mac80211] Jun 1 17:19:49 test kernel: [10239.848775] [<ffffffffa03f6e67>] ieee80211_offchannel_return+0x187/0x1f0 [mac80211] Jun 1 17:19:49 test kernel: [10239.848802] [<ffffffffa0401b81>] ieee80211_work_work+0x5e1/0x18c0 [mac80211] Jun 1 17:19:49 test kernel: [10239.848824] [<ffffffff8106e010>] run_workqueue+0xb0/0x1d0 Jun 1 17:19:49 test kernel: [10239.848830] [<ffffffff8106e1cb>] worker_thread+0x9b/0x100 Jun 1 17:19:49 test kernel: [10239.848836] [<ffffffff8107167e>] kthread+0x8e/0xa0 Jun 1 17:19:49 test kernel: [10239.848841] [<ffffffff81003df4>] kernel_thread_helper+0x4/0x10 Jun 1 17:19:49 test kernel: [10239.848854] ---[ end trace 5490dac9b02f8a18 ]--- Jun 1 17:19:50 test kernel: [10240.854337] ath: Failed to stop TX DMA, queues=0x001! ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- ---------------------------------------------------------------------------- Beyond this point, the system is rendered useless and only option left is to reboot the system Would highly appreciate, if the following queries are clarified 1. Is this a known issue? Is there anyway to reproduce it in a lab environment 2. Is there a fix available in latest/recent version of compat or backports. In which version of compat is thee fix available? 3. If I disable dynamic power save in mac80211, would it solve my problem? regards TGK -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html