On 12/06/2010 11:36 AM, Luis R. Rodriguez wrote:
Can you clarify the status of this issue. It remains unclear to me from your above description how things are going. As I read it some things look OK now but you still get a warning.
Ok, since you asked :) I worked on this over the weekend and this morning. I had all sorts of issues until I realized that I had one STA with non-configured SSID. It sometimes connected to one /a AP and the other STAs attempted to connect to another /n (on entirely different band) AP. I basically got zero stations associated for any length of time due to constant channel switching. No crashes, but lots of warnings about DMA failing to stop. Now..I've fixed this configuration issue (and adding steps to help prevent this mis-configuration again). With 16 properly configured non-encrypted stations, running with wpa-supplicant with netlink driver & sharing scan results, the interfaces quickly associate. However, I do continue to see DMA warnings such as these (I had picked up my portable phone, and it knocked all the interfaces offline ..here they are coming back up after I hung up the phone). Please note that I ported Felix's 2.6.37 patch he posted this morning to wireless-testing and have applied it. I'm highly tempted to just make that a WARN_ON_ONCE so at least my logs aren't spammed so heavily with the recv.c:531 DMA warning. Dec 6 11:32:15 atom kernel: sta2: direct probe to 00:18:e7:cb:ad:6e timed out Dec 6 11:32:15 atom kernel: sta14: direct probe to 00:18:e7:cb:ad:6e timed out Dec 6 11:32:15 atom kernel: ieee80211 wiphy0: device now idle Dec 6 11:32:15 atom kernel: ieee80211 wiphy0: device no longer idle - scanning Dec 6 11:32:15 atom kernel: start_sw_scan: running-other-vifs: 0 running-station-vifs: 16, associated-stations: 0 scanning all channels. Dec 6 11:32:17 atom kernel: ieee80211 wiphy0: device now idle Dec 6 11:32:22 atom kernel: ieee80211 wiphy0: device no longer idle - scanning Dec 6 11:32:22 atom kernel: start_sw_scan: running-other-vifs: 0 running-station-vifs: 16, associated-stations: 0 scanning all channels. Dec 6 11:32:24 atom kernel: ieee80211 wiphy0: device now idle Dec 6 11:32:29 atom kernel: ieee80211 wiphy0: device no longer idle - scanning Dec 6 11:32:29 atom kernel: start_sw_scan: running-other-vifs: 0 running-station-vifs: 16, associated-stations: 0 scanning all channels. Dec 6 11:32:29 atom kernel: ath: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x42000020 Dec 6 11:32:29 atom kernel: ------------[ cut here ]------------ Dec 6 11:32:29 atom kernel: WARNING: at /home/greearb/git/linux.wireless-testing/drivers/net/wireless/ath/ath9k/recv.c:531 ath_stoprecv+0x90/0x9a [ath9) Dec 6 11:32:29 atom kernel: Hardware name: 945GM Dec 6 11:32:29 atom kernel: Could not stop RX, we could be confusing the DMA engine when we start RX up Dec 6 11:32:29 atom kernel: Modules linked in: michael_mic ath9k mac80211 ath9k_common ath9k_hw ath cfg80211 arc4 8021q garp stp llc macvlan pktgen isc] Dec 6 11:32:29 atom kernel: Pid: 2732, comm: kworker/u:2 Tainted: G W 2.6.37-rc4-wl+ #17 Dec 6 11:32:29 atom kernel: Call Trace: Dec 6 11:32:29 atom kernel: [<78436fbd>] warn_slowpath_common+0x77/0x8c Dec 6 11:32:29 atom kernel: [<fb7a125e>] ? ath_stoprecv+0x90/0x9a [ath9k] Dec 6 11:32:29 atom kernel: [<fb7a125e>] ? ath_stoprecv+0x90/0x9a [ath9k] Dec 6 11:32:29 atom kernel: [<7843704e>] warn_slowpath_fmt+0x2e/0x30 Dec 6 11:32:29 atom kernel: [<fb7a125e>] ath_stoprecv+0x90/0x9a [ath9k] Dec 6 11:32:29 atom kernel: [<fb7a0182>] ath_set_channel+0x94/0x1f2 [ath9k] Dec 6 11:32:29 atom kernel: [<7845a405>] ? mark_held_locks+0x47/0x5f Dec 6 11:32:29 atom kernel: [<7878e7cb>] ? _raw_spin_unlock_irqrestore+0x3c/0x48 Dec 6 11:32:29 atom kernel: [<fb7a067a>] ath9k_config+0x39a/0x479 [ath9k] Dec 6 11:32:29 atom kernel: [<fb6caaaa>] ieee80211_hw_config+0x11b/0x125 [mac80211] Dec 6 11:32:29 atom kernel: [<fb6cef1b>] ieee80211_scan_work+0x29e/0x3f7 [mac80211] Dec 6 11:32:29 atom kernel: [<78446f63>] ? process_one_work+0x13e/0x2bf Dec 6 11:32:29 atom kernel: [<78446fd4>] process_one_work+0x1af/0x2bf Dec 6 11:32:29 atom kernel: [<78446f63>] ? process_one_work+0x13e/0x2bf Dec 6 11:32:29 atom kernel: [<fb6cec7d>] ? ieee80211_scan_work+0x0/0x3f7 [mac80211] Dec 6 11:32:29 atom kernel: [<78448722>] worker_thread+0xf9/0x1bf Dec 6 11:32:29 atom kernel: [<78448629>] ? worker_thread+0x0/0x1bf Dec 6 11:32:29 atom kernel: [<7844b252>] kthread+0x62/0x67 Dec 6 11:32:29 atom kernel: [<7844b1f0>] ? kthread+0x0/0x67 Dec 6 11:32:29 atom kernel: [<784036c6>] kernel_thread_helper+0x6/0x1a Dec 6 11:32:29 atom kernel: ---[ end trace 617a0f44fc30537b ]--- Dec 6 11:32:29 atom kernel: ath: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x42000020 On module unload, I sometimes see lots of more scary looking DMA warnings, ..but again, system seems stable aside from the noise in the logs. I will capture these and post them next time I get a clean set of them (previous ones were on the mis-configured STA scenario..maybe they only happen when you unload while driver is scanning or something like that). Thanks, Ben -- Ben Greear <greearb@xxxxxxxxxxxxxxx> Candela Technologies Inc http://www.candelatech.com -- 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
