Return-path: Received: from mail-db5eur01on0118.outbound.protection.outlook.com ([104.47.2.118]:51456 "EHLO EUR01-DB5-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1032204AbeBNQ0o (ORCPT ); Wed, 14 Feb 2018 11:26:44 -0500 From: Jean Pierre TOSONI To: Kalle Valo CC: "linux-wireless@vger.kernel.org" , "ath9k-devel@qca.qualcomm.com" Subject: [PATCH v2] ath9k: mark RSSI as invalid if frame received during channel setup Date: Wed, 14 Feb 2018 16:26:42 +0000 Message-ID: (sfid-20180214_172648_842860_6A5D18EB) Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: ath9k returns a wrong RSSI value for frames received in a 30ms time window after a channel change. The correct value is typically 10dB below the returned value. This was found with a Atheros AR9300 Rev:3 chip (WLE350NX / JWX6083 cards), during offchannel scans. Mark the signal value as invalid in this case. Signed-off-by: Jean Pierre TOSONI --- V2: replace LEDE patch with due kernel patch (with excuses to Kalle Valo) drivers/net/wireless/ath/ath9k/ani.c | 1 + drivers/net/wireless/ath/ath9k/common.c | 10 ++++++++++ drivers/net/wireless/ath/ath9k/hw.h | 1 + 3 files changed, 12 insertions(+), 0 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/ani.c b/drivers/net/wireless/at= h/ath9k/ani.c index 5214dd7..a7e07ed 100644 --- a/drivers/net/wireless/ath/ath9k/ani.c +++ b/drivers/net/wireless/ath/ath9k/ani.c @@ -317,6 +317,7 @@ void ath9k_ani_reset(struct ath_hw *ah, bool is_scannin= g) return; =20 BUG_ON(aniState =3D=3D NULL); + ah->chan_stable_time =3D jiffies + (30*HZ)/1000; /* 30ms */ ah->stats.ast_ani_reset++; =20 ofdm_nil =3D max_t(int, ATH9K_ANI_OFDM_DEF_LEVEL, diff --git a/drivers/net/wireless/ath/ath9k/common.c b/drivers/net/wireless= /ath/ath9k/common.c index 099f3d4..7e5f7a3 100644 --- a/drivers/net/wireless/ath/ath9k/common.c +++ b/drivers/net/wireless/ath/ath9k/common.c @@ -221,6 +221,16 @@ void ath9k_cmn_process_rssi(struct ath_common *common, int i, j; =20 /* + * RSSI is not available before 30ms after reset on ath9k. + */ + if (time_before(jiffies, ah->chan_stable_time)) { + ath_dbg(common, ANY, "early frame rssi=3D%d\n",rx_stats->rs_rssi); + rxs->flag |=3D RX_FLAG_NO_SIGNAL_VAL; + return; + } + ah->chan_stable_time =3D jiffies; /* advance stable time to cop with jiff= ies wraparound */ + + /* * RSSI is not available for subframes in an A-MPDU. */ if (rx_stats->rs_moreaggr) { diff --git a/drivers/net/wireless/ath/ath9k/hw.h b/drivers/net/wireless/ath= /ath9k/hw.h index 9804a24..ec07da9 100644 --- a/drivers/net/wireless/ath/ath9k/hw.h +++ b/drivers/net/wireless/ath/ath9k/hw.h @@ -809,6 +809,7 @@ struct ath_hw { =20 bool reset_power_on; bool htc_reset_init; + unsigned long chan_stable_time; =20 enum nl80211_iftype opmode; enum ath9k_power_mode power_mode; --=20 1.7.2.5