On Mon, May 26, 2014 at 11:00 AM, Emmanuel Grumbach <egrumbach@xxxxxxxxx> wrote: >>>>>>>> Every now and then, my connection drops out. From wireshark on the >>>>>>>> station, it looks like traffic from the AP to the STA is coming >>>>>>>> through but traffic from the STA to the AP is not. I could be wrong >>>>>>>> here, though. Nothing is logged in either machine's kernel log. >>>>>>>> After 5 seconds to a couple minutes, everything starts working again. >>>>>>>> >>>>>>>> A couple of Apple devices using the same radio on the same AP seem to work fine. >>>>>>>> >>>>>>>> Any advice for debugging this? I don't know where to start. >>>>>>> >>>>>>> I caught one of the stalls with iwlwifi debugging on. I've attached >>>>>>> the dmesg. The stall ended ten seconds or so before the end of this >>>>>>> trace. Is this an indication that something's wrong with iwlwifi? >>>>>>> >>>>>>> [151258.096091] iwlwifi 0000:03:00.0: U iwlagn_good_plcp_health plcp health thre >>>>>>> shold 50 delta 96 msecs 103 >>>>>>> [151258.096095] iwlwifi 0000:03:00.0: U iwl_force_rf_reset perform radio reset. >>>>>>> >>>>>> Can you please disable powersave? >>>>>> It seems that it should be disabled by default, but you enabled it? >>>>>> I might be confused though... Looking again at the code... >>>>> >>>>> This? >>>>> >>>>> $ cat /sys/module/iwlwifi/parameters/power_save >>>>> N >>>>> >>>>> I have pcie_aspm.policy=powersave, but I don't think that should >>>>> matter. Or am I missing something? >>>> >>>> That should be ok. >>> >>> Does this help? >>> >>> diff --git a/drivers/net/wireless/iwlwifi/dvm/power.c >>> b/drivers/net/wireless/iwlwifi/dvm/power.c >>> index f2c1439..e5a6b70 100644 >>> --- a/drivers/net/wireless/iwlwifi/dvm/power.c >>> +++ b/drivers/net/wireless/iwlwifi/dvm/power.c >>> @@ -288,6 +288,9 @@ static void iwl_power_build_cmd(struct iwl_priv *priv, >>> bool enabled = priv->hw->conf.flags & IEEE80211_CONF_PS; >>> int dtimper; >>> >>> + iwl_power_sleep_cam_cmd(priv, cmd); >>> + return; >>> + >>> dtimper = priv->hw->conf.ps_dtim_period ?: 1; >>> >>> if (priv->wowlan) >> >> This patch has survived for about 15 minutes on 3.15-rc. It certainly >> has some effect: pinging from the AP to the STA now takes a consistent >> ~3.8ms instead of taking varying amounts of time between 5 and 200 ms >> or so. >> >> I wonder if this is something 802.11n/802.11ac-specific? I remember >> having all kinds of problems with 802.11n on this laptop that were >> resolved by turning off 11n or turning off power saving. >> > > well... my patch really turns off power saving. The hard way. > But since you are having issues - I guess I'll post it and disable > power save for these devices. Note that today most of the power save > features are disabled anyway. Would it make sense to do this only when connected to a VHT-supporting AP or whatever AP feature is probably triggering the problem? *sigh* I'd just plug in a new PCIe wireless card, except that I think that my evil BIOS will refuse to boot if I do that. --Andy -- 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
