Re: memory clobber in rx path, maybe related to ath9k.

[Ben Greear <greearb@candelatech.com>]

I had a chance to try your latest patch on a different machine and AP.  This time,
I was using 130 or so stations, but no encryption (no supplicant).

I saw these exceptions below.  The warn-on hits the !stopped check in ath_stoprecv.

The system didn't crash, but all of the STAs soon dis-associated because of "inactivity".
I haven't checked if that is some issue with my AP or what..


bool ath_stoprecv(struct ath_softc *sc)
{
	struct ath_hw *ah = sc->sc_ah;
	bool stopped;

	spin_lock_bh(&sc->rx.rxbuflock);
	ath9k_hw_stoppcurecv(ah);
	ath9k_hw_setrxfilter(ah, 0);
	stopped = ath9k_hw_stopdmarecv(ah);

	if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
		ath_edma_stop_recv(sc);
	else
		sc->rx.rxlink = NULL;
	spin_unlock_bh(&sc->rx.rxbuflock);

	WARN_ON(!stopped);
	return stopped;
}


ADDRCONF(NETDEV_UP): sta130: link is not ready
sta90: no IPv6 routers present
ath: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x40000020
------------[ cut here ]------------
WARNING: at /home/greearb/git/linux.wireless-testing/drivers/net/wireless/ath/ath9k/recv.c:532 ath_stoprecv+0x80/0x87 [ath9k]()
Hardware name: 945GM
Modules linked in: 8021q garp stp llc michael_mic macvlan pktgen iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi nfs lockd fscache nfs_acl auth_rpcgss 
sunrpc p4_clockmod ipv6 uinput arc4 ecb ath9k snd_intel8x0 mac80211 snd_ac97_codec ac97_bus snd_seq snd_seq_device ath9k_common snd_pcm ath9k_hw ath snd_timer 
microcode pcspkr cfg80211 i2c_i801 snd soundcore snd_page_alloc serio_raw e1000e iTCO_wdt iTCO_vendor_support yenta_socket floppy i915 drm_kms_helper drm 
i2c_algo_bit i2c_core video output [last unloaded: ipt_addrtype]
Pid: 5, comm: kworker/u:0 Tainted: G        W   2.6.36-rc8-wl+ #12
Call Trace:
  [<c0434647>] warn_slowpath_common+0x65/0x7a
  [<f9450e38>] ? ath_stoprecv+0x80/0x87 [ath9k]
  [<c043466b>] warn_slowpath_null+0xf/0x13
  [<f9450e38>] ath_stoprecv+0x80/0x87 [ath9k]
  [<f944f580>] ath_set_channel+0x99/0x1ff [ath9k]
  [<f94502b2>] ath9k_config+0x305/0x3d8 [ath9k]
  [<f9246a2e>] ieee80211_hw_config+0x11b/0x125 [mac80211]
  [<f924aa51>] ieee80211_scan_work+0x29e/0x3ed [mac80211]
  [<c0443d72>] ? process_one_work+0x145/0x295
  [<c0443dbc>] process_one_work+0x18f/0x295
  [<c0443d72>] ? process_one_work+0x145/0x295
  [<f924a7b3>] ? ieee80211_scan_work+0x0/0x3ed [mac80211]
  [<c04453e5>] worker_thread+0xf9/0x1b8
  [<c04452ec>] ? worker_thread+0x0/0x1b8
  [<c0447d2f>] kthread+0x62/0x67
  [<c0447ccd>] ? kthread+0x0/0x67
  [<c0403506>] kernel_thread_helper+0x6/0x1a
---[ end trace bc53fa727ee2ae42 ]---
ath: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x42000020
ath: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x40000020
------------[ cut here ]------------
WARNING: at /home/greearb/git/linux.wireless-testing/drivers/net/wireless/ath/ath9k/recv.c:532 ath_stoprecv+0x80/0x87 [ath9k]()
Hardware name: 945GM
Modules linked in: 8021q garp stp llc michael_mic macvlan pktgen iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi nfs lockd fscache nfs_acl auth_rpcgss 
sunrpc p4_clockmod ipv6 uinput arc4 ecb ath9k snd_intel8x0 mac80211 snd_ac97_codec ac97_bus snd_seq snd_seq_device ath9k_common snd_pcm ath9k_hw ath snd_timer 
microcode pcspkr cfg80211 i2c_i801 snd soundcore snd_page_alloc serio_raw e1000e iTCO_wdt iTCO_vendor_support yenta_socket floppy i915 drm_kms_helper drm 
i2c_algo_bit i2c_core video output [last unloaded: ipt_addrtype]
Pid: 41, comm: kworker/u:2 Tainted: G        W   2.6.36-rc8-wl+ #12
Call Trace:
  [<c0434647>] warn_slowpath_common+0x65/0x7a
  [<f9450e38>] ? ath_stoprecv+0x80/0x87 [ath9k]
  [<c043466b>] warn_slowpath_null+0xf/0x13
  [<f9450e38>] ath_stoprecv+0x80/0x87 [ath9k]
  [<f944f580>] ath_set_channel+0x99/0x1ff [ath9k]
  [<f94502b2>] ath9k_config+0x305/0x3d8 [ath9k]
  [<f9246a2e>] ieee80211_hw_config+0x11b/0x125 [mac80211]
  [<f924aa51>] ieee80211_scan_work+0x29e/0x3ed [mac80211]
  [<c0443d72>] ? process_one_work+0x145/0x295
  [<c0443dbc>] process_one_work+0x18f/0x295
  [<c0443d72>] ? process_one_work+0x145/0x295
  [<f924a7b3>] ? ieee80211_scan_work+0x0/0x3ed [mac80211]
  [<c04453e5>] worker_thread+0xf9/0x1b8
  [<c04452ec>] ? worker_thread+0x0/0x1b8
  [<c0447d2f>] kthread+0x62/0x67
  [<c0447ccd>] ? kthread+0x0/0x67
  [<c0403506>] kernel_thread_helper+0x6/0x1a
---[ end trace bc53fa727ee2ae43 ]---
ath: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x42000020
sta126: direct probe to 00:18:e7:cb:ad:6e (try 1)
sta130: direct probe to 00:18:e7:cb:ad:6e (try 1)
sta91: no IPv6 routers present
sta126: direct probe to 00:18:e7:cb:ad:6e (try 2)
sta130: direct probe to 00:18:e7:cb:ad:6e (try 2)
sta126: direct probe to 00:18:e7:cb:ad:6e (try 3)
sta130: direct probe to 00:18:e7:cb:ad:6e (try 3)
sta126: direct probe to 00:18:e7:cb:ad:6e timed out
sta130: direct probe to 00:18:e7:cb:ad:6e timed out
sta92: no IPv6 routers present
...


Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com