Return-path: Received: from mail-la0-f45.google.com ([209.85.215.45]:46061 "EHLO mail-la0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751118Ab3KHOSx (ORCPT ); Fri, 8 Nov 2013 09:18:53 -0500 Received: by mail-la0-f45.google.com with SMTP id el20so1780742lab.4 for ; Fri, 08 Nov 2013 06:18:51 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: <526E20EA.9090203@rempel-privat.de> Date: Fri, 8 Nov 2013 08:18:51 -0600 Message-ID: (sfid-20131108_151858_192704_0B1AC6BA) Subject: Re: I always need a miracle to connect with iwlwifi From: Felipe Contreras To: Krishna Chaitanya Cc: Oleksij Rempel , ilw@linux.intel.com, "hostap@lists.shmoo.com" , linux-wireless Mailing List Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Fri, Nov 8, 2013 at 8:06 AM, Krishna Chaitanya wrote: > On Fri, Nov 8, 2013 at 6:44 PM, Felipe Contreras > wrote: >> On Fri, Nov 8, 2013 at 2:35 AM, Felipe Contreras >> wrote: >>> On Sat, Nov 2, 2013 at 2:05 PM, Krishna Chaitanya >>> wrote: >>> >>>> Also one more thing you said N900 uses mac80211 and it has no issues, but as >>>> its a embedded device it might running an older kernel where the >>>> handling might be >>>> different, so we need to try with the same kernel you are facing an >>>> issue with the >>>> a driver which advertises IEEE80211_HW_NEED_DTIM_BEFORE_ASSOC. >>> >>> Yes it was running an older kernel, but I just compiled v3.12 and ran >>> it on the N900, and still everything works fine. >>> >>>> (or) if you a have a compilation environment try commenting the advertisement of >>>> IEEE80211_HW_NEED_DTIM_BEFORE_ASSOC in the iwlwifi DVM driver and >>>> try to reproduce the issue. >>> >>> After commenting that flag everything works fine :) > > Oh, great. That was just to corner the problem, that means we are not getting > the required beacon before the association, but we only wait for 1 beacon here > may be we to wait for some number of beacons before giving up the association?? > > Johannes?? But we are receiving 0 beacons, waiting for more than 1 won't help. BTW, why NEED_DTIM_BEFORE_ASSOC if the device doesn't *need* the DTIM before the association? >>> What are the next steps? >> >> I tried to add some debugging to see what's going on, and indeed the >> beacon packets are lost, I added debugging as low in the chain as I >> could (iwlagn_rx_reply_rx()), and I don't see them there. However, >> when I enable the monitor mode, I see them. What's going on? > > In the captures you shared all the beacons are malformed, so > probably they failed the CRC check. iwlwifi drops all the CRC failed > packets. (doth MVM and DVM) Before iwlagn_rx_reply_rx()? > Not sure how you are receiving the beacons in the monitor mode. I don't know what kismet does, but I can see my debugging is printing them. > BTW did you tried capturing the beacons in other devices and see if they > are really malformed, or is it just iwlwifi interpreting them wrongly.? I haven't managed to do that yet. This is what I'm doing: --- a/drivers/net/wireless/iwlwifi/dvm/rx.c +++ b/drivers/net/wireless/iwlwifi/dvm/rx.c @@ -919,6 +919,11 @@ static int iwlagn_rx_reply_rx(struct iwl_priv *priv, ampdu_status = iwlagn_translate_rx_status(priv, le32_to_cpu(rx_pkt_status)); + if (ieee80211_is_beacon(header->frame_control)) { + print_hex_dump(KERN_INFO, "iwlwifi: dump: ", DUMP_PREFIX_OFFSET, + 16, 1, header, len, true); + } + if ((unlikely(phy_res->cfg_phy_cnt > 20))) { IWL_DEBUG_DROP(priv, "dsp size out of range [0,20]: %d\n", phy_res->cfg_phy_cnt); -- Felipe Contreras