| Message ID | 7d04126f-0f24-b4a4-6d13-6f52046d7671@neratec.com |
|---|---|
| State | New |
| Headers | show |
On 21 November 2016 at 15:41, Zefir Kurtisi <zefir.kurtisi@neratec.com> wrote: > 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. Good point. I guess set_channel could be oversimplified as well. I mean, it makes sense to consider radar and spectral mutually exclusive if they use the same phyerr code. However some chips actually seem (as per the comment I mentioned) to distinguish the two so I don't know if the "mutually exclusive" is true for all chips per se. Just thinking out loud. I also wonder if calling ieee80211_radar_detect() should have any effect if there are no radar operated interfaces in the first place? Michał
From c24edf82e1f509490ba9dd3e34eec3ac3b309321 Mon Sep 17 00:00:00 2001 From: Zefir Kurtisi <zefir.kurtisi@neratec.com> 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