Return-path: Received: from mail.neratec.com ([46.140.151.2]:17820 "EHLO mail.neratec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753869AbcKUOrq (ORCPT ); Mon, 21 Nov 2016 09:47:46 -0500 Subject: Re: [PATCH] ath9k: Prevent radar detection and spectral scan to be used concurrently To: Benjamin Berg , Kalle Valo References: <20161121140423.24367-1-benjamin@sipsolutions.net> Cc: ath9k-devel@lists.ath9k.org, linux-wireless@vger.kernel.org, Mathias Kretschmer , Simon Wunderlich From: Zefir Kurtisi Message-ID: <7d04126f-0f24-b4a4-6d13-6f52046d7671@neratec.com> (sfid-20161121_154750_012117_8212F7EB) Date: Mon, 21 Nov 2016 15:41:43 +0100 MIME-Version: 1.0 In-Reply-To: <20161121140423.24367-1-benjamin@sipsolutions.net> Content-Type: multipart/mixed; boundary="------------81DB7B8680E9662AC7B071A0" Sender: linux-wireless-owner@vger.kernel.org List-ID: This is a multi-part message in MIME format. --------------81DB7B8680E9662AC7B071A0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit On 11/21/2016 03:04 PM, Benjamin Berg wrote: > In the case that a spectral scan is enabled the PHY errors sent by the > hardware as part of the scanning might trigger the radar detection and > channels might be marked as 'unusable' incorrectly. This patch fixes > the issue by preventing the spectral scan to be enabled if DFS is used > and only analysing the PHY errors for DFS if radar detection is enabled. > > [...] >From the relevant source code portion in channel.c:ath_set_channel() 80 /* Enable radar pulse detection if on a DFS channel. Spectral 81 * scanning and radar detection can not be used concurrently. 82 */ 83 if (hw->conf.radar_enabled) { 84 u32 rxfilter; 85 86 rxfilter = ath9k_hw_getrxfilter(ah); 87 rxfilter |= ATH9K_RX_FILTER_PHYRADAR | 88 ATH9K_RX_FILTER_PHYERR; 89 ath9k_hw_setrxfilter(ah, rxfilter); 90 ath_dbg(common, DFS, "DFS enabled at freq %d\n", 91 chan->center_freq); 92 } else { 93 /* perform spectral scan if requested. */ 94 if (test_bit(ATH_OP_SCANNING, &common->op_flags) && 95 sc->spec_priv.spectral_mode == SPECTRAL_CHANSCAN) 96 ath9k_cmn_spectral_scan_trigger(common, &sc->spec_priv); 97 } it seems that spectral can't ever be activated while operating on a DFS channel. If you need to catch the opposite case, i.e. prevent feeding pseudo-radar pulses into the pattern detector, you just need to ensure that they depend on hw->conf.radar_enabled. A patch like the attached one should be enough. Cheers, Zefir --------------81DB7B8680E9662AC7B071A0 Content-Type: text/x-patch; name="0001-ath9k-feed-DFS-detector-only-if-operating-on-radar-c.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename*0="0001-ath9k-feed-DFS-detector-only-if-operating-on-radar-c.pa"; filename*1="tch" >From c24edf82e1f509490ba9dd3e34eec3ac3b309321 Mon Sep 17 00:00:00 2001 From: Zefir Kurtisi Date: Mon, 21 Nov 2016 15:33:45 +0100 Subject: [PATCH] ath9k: feed DFS detector only if operating on radar channel --- drivers/net/wireless/ath/ath9k/recv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c index 6697342..e4701a7 100644 --- a/drivers/net/wireless/ath/ath9k/recv.c +++ b/drivers/net/wireless/ath/ath9k/recv.c @@ -867,7 +867,8 @@ static int ath9k_rx_skb_preprocess(struct ath_softc *sc, * can be dropped. */ if (rx_stats->rs_status & ATH9K_RXERR_PHY) { - ath9k_dfs_process_phyerr(sc, hdr, rx_stats, rx_status->mactime); + if (hw->conf.radar_enabled) + ath9k_dfs_process_phyerr(sc, hdr, rx_stats, rx_status->mactime); if (ath_cmn_process_fft(&sc->spec_priv, hdr, rx_stats, rx_status->mactime)) RX_STAT_INC(rx_spectral); -- 2.7.4 --------------81DB7B8680E9662AC7B071A0--