I have tons of 'brcms_c_prec_enq_head: No where to go, prec == 4' messages in dmesg, practically they overwrite all other messages from the buffer: > [root@dhcp-31-100 ~]# dmesg | grep -c 'brcms_c_prec_enq_head: No where to go, > prec == 4' > 4226 This happen when downloading file using wget through WPA2-enterprise 11g network.
Created attachment 81791 [details] /my-v3.5.config Kernel config file.
Adapter: a0:00.0 Network controller [0280]: Broadcom Corporation BCM43224 802.11a/b/g/n [14e4:4353] (rev 01) Subsystem: Dell Wireless 1520 Half-size Mini PCIe Card [1028:000e] Physical Slot: 5 Flags: bus master, fast devsel, latency 0, IRQ 26 Memory at f3600000 (64-bit, non-prefetchable) [size=16K] Capabilities: <access denied> Kernel driver in use: bcma-pci-bridge Kernel modules: bcma
Created attachment 83821 [details] dmesg-3.6-patched.txt Dmesg from 3.6 kernel with patch from https://bugzilla.kernel.org/show_bug.cgi?id=48391#c16 There are still lots of "No where to go" messages and when NM periodic scan trigger there are additional WARNINGs.
Some more detailed network parameters: WPA2-Enterprise, authentication: PEAP v1, inner authentication: GTC. Corresponding "iw dev wlan0 scan" output: BSS 00:3a:98:a0:30:51 (on wlan8) -- associated TSF: 594862694797 usec (6d, 21:14:22) freq: 2412 beacon interval: 100 capability: ESS Privacy ShortPreamble ShortSlotTime (0x0431) signal: -49.00 dBm SSID: Red Hat Supported rates: 1.0* 2.0* 5.5* 6.0 9.0 11.0* 12.0 18.0 DS Parameter set: channel 1 Country: CZ (in/outdoor), data: 01 0d 14 ERP: <no flags> RSN: * Version: 1 * Group cipher: CCMP * Pairwise ciphers: CCMP * Authentication suites: IEEE 802.1X 00-40-96:0 * Capabilities: 4-PTKSA-RC 4-GTKSA-RC (0x0028) Extended supported rates: 24.0 36.0 48.0 54.0 WMM: * Parameter version 1 * u-APSD * BE: CW 15-1023, AIFSN 3 * BK: CW 15-1023, AIFSN 7 * VI: CW 7-15, AIFSN 2, TXOP 3008 usec * VO: acm CW 3-7, AIFSN 2, TXOP 1504 usec
does this only happen when using WPA2-Enterprise? what throughput are you reaching? could you post log with timestamps so we can judge how long this packet dropping lasts?
"No where to go" messages occurs _sporadically_ on some other networks too. I did not get "WARNING at brcms_ops_flush" on other network. Throughput is about 1MBytes/s , it decrease to about 500kBytes/s when errors start to show up in dmesg.
Created attachment 84261 [details] dmesg-3.6-patched-timestamps.txt
Created attachment 84651 [details] nowhere to go patch 1 i cannot really reproduce such a flood of messages here is a patch that modifies packet dropping policy could you try it? preferably with one from Bug #48391
Created attachment 85311 [details] dmesg.patched.txt Dmesg from 3.7-rc3 kernel with nowhere.patch and ops_flush.patch .
Created attachment 85321 [details] full_dmesg.patched.txt.gz Since dmesg wrapped out, I'm attaching full log started from brcmsmac module load.
Created attachment 85331 [details] Rework tx code to avoid internal buffering of packets I have: 0d:00.0 Network controller: Broadcom Corporation BCM4313 802.11b/g/n Wireless LAN Controller (rev 01) When these "Nowhere to go" errors started to appear, not only performance decreased, but connection stopped to work at all. It seems that this patch fixes the problem: https://patchwork.kernel.org/patch/1651801/ I applied it to kernel 3.6.4. Now I don't see these "Nowhere to go" errors. Downloaded 4GB iso image using Transmission and didn't notice any problems.
I confirm the fix, I'm not able to reproduce the problem any longer.