Return-path: Received: from mail-wi0-f175.google.com ([209.85.212.175]:36201 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751515AbbFOFgN convert rfc822-to-8bit (ORCPT ); Mon, 15 Jun 2015 01:36:13 -0400 Received: by wigg3 with SMTP id g3so65295515wig.1 for ; Sun, 14 Jun 2015 22:36:12 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <557AFC9D.3020109@candelatech.com> References: <5579F87F.4070601@candelatech.com> <557A1BE9.7070305@candelatech.com> <557AFC9D.3020109@candelatech.com> Date: Mon, 15 Jun 2015 07:36:11 +0200 Message-ID: (sfid-20150615_073617_857559_988F656F) Subject: Re: Question on beacon-miss offloading. From: Michal Kazior To: Ben Greear Cc: ath10k , "linux-wireless@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 12 June 2015 at 17:37, Ben Greear wrote: > On 06/11/2015 11:03 PM, Michal Kazior wrote: >> On 12 June 2015 at 01:38, Ben Greear wrote: >>> On 06/11/2015 02:07 PM, Ben Greear wrote: >>>> In my ath10k CT firmware, I am disabling the beacon-miss offloading >>>> to save space and because it will not work with lots of virtual >>>> stations. >>>> >>>> But, it must be that I need some way to tell the stack that this >>>> feature is not enabled, because when suddenly kill my AP, then >>>> the ath10k station connected to it shows endless 'beacon loss' events >>>> in 'iw events' output, but it never actually loses connection. >>>> >>>> Stock firmware works fine, so probably I just need to disable >>>> some feature flag when registering the ath10k hardware >>>> when using CT firmware. >>>> >>>> With stock firmware, I see a quick dissassociation due to inactivity. >>>> >>>> I am having poor luck finding how a driver tells the stack >>>> it has beacon miss offload or not, so, does anyone know how >>>> this is controlled? >>> >>> I still am not sure why stock firmware works, but it appears >>> the reason mine is failing is that the ACK status for mgt frames >>> is always set to TRUE since the ath10k wmi-mgt-tx API is so >>> lame. So, mac80211 does a probe, ath10k lies and says it was >>> acked, and mac80211 then things all is well for another few >>> seconds. >> >> mac80211 shouldn't do a Probe Req to an AP on beacon loss because >> ath10k advertises it supports tx-status report. Hence mac80211 should >> use NullFunc frames which shouldn't go through wmi-mgmt-tx but htt >> tx-frm. >> >> But then again: NullFunc status reporting via htt tx-frm was broken on >> 10.1 if memory serves right. I believe it was fixed in 10.2 or 10.2.4. >> >> This problem has been effectively obscured on stock 10.1 by the >> offloaded beacon miss. > > Thanks for the hint. I was able to fix my firmware to properly > return htt tx status, and now it appears to work properly. > > A quick throughput test works as well, so hopefully no regressions. > > I guess the NulFunc related comment is incorrect for 10.1 stock firmware? > > Maybe some others? > > static void ath10k_tx_htt(struct ath10k *ar, struct sk_buff *skb) > { > struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; > int ret = 0; > > if (ar->htt.target_version_major >= 3) { > /* Since HTT 3.0 there is no separate mgmt tx command */ > ret = ath10k_htt_tx(&ar->htt, skb); > goto exit; > } > > if (ieee80211_is_mgmt(hdr->frame_control)) { > if (test_bit(ATH10K_FW_FEATURE_HAS_WMI_MGMT_TX, > ar->fw_features)) { > if (skb_queue_len(&ar->wmi_mgmt_tx_queue) >= > ATH10K_MAX_NUM_MGMT_PENDING) { > ath10k_warn(ar, "reached WMI management transmit queue limit\n"); > ret = -EBUSY; > goto exit; > } > > skb_queue_tail(&ar->wmi_mgmt_tx_queue, skb); > ieee80211_queue_work(ar->hw, &ar->wmi_mgmt_tx_work); > } else { > ret = ath10k_htt_mgmt_tx(&ar->htt, skb); > } > } else if (!test_bit(ATH10K_FW_FEATURE_HAS_WMI_MGMT_TX, > ar->fw_features) && > ieee80211_is_nullfunc(hdr->frame_control)) { > /* FW does not report tx status properly for NullFunc frames > * unless they are sent through mgmt tx path. mac80211 sends > * those frames when it detects link/beacon loss and depends > * on the tx status to be correct. */ > ret = ath10k_htt_mgmt_tx(&ar->htt, skb); > } else { > ret = ath10k_htt_tx(&ar->htt, skb); > } The NullFunc workaround was originally done for 999.999.0.636 but should be true for 10.1 as well with the sole exception the latter doesn't have htt-mgmt-tx to workaround the problem. Michał