Return-path: Received: from mail-la0-f43.google.com ([209.85.215.43]:34605 "EHLO mail-la0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932197AbbH0MrK (ORCPT ); Thu, 27 Aug 2015 08:47:10 -0400 Received: by laba3 with SMTP id a3so11642307lab.1 for ; Thu, 27 Aug 2015 05:47:08 -0700 (PDT) From: Michal Kazior To: ath10k@lists.infradead.org Cc: linux-wireless@vger.kernel.org, Michal Kazior Subject: [PATCH 2/2] ath10k: fix mu-mimo rx status reporting Date: Thu, 27 Aug 2015 14:47:33 +0200 Message-Id: <1440679653-20289-2-git-send-email-michal.kazior@tieto.com> (sfid-20150827_144718_901624_8B3EF825) In-Reply-To: <1440679653-20289-1-git-send-email-michal.kazior@tieto.com> References: <1440679653-20289-1-git-send-email-michal.kazior@tieto.com> Sender: linux-wireless-owner@vger.kernel.org List-ID: MU-MIMO Rx involves different interpretation of the VHT-SIG-A compared to SU-MIMO. The incorrect interpretation led ath10k to report VHT MCS values greater than 9 which subsequently prompted mac80211 to drop such frames. This effectively broke Rx with MU-MIMO in many cases and manifested with a kernel warning in the log which looked like this: [ 14.552520] WARNING: CPU: 2 PID: 0 at net/mac80211/rx.c:3578 ieee80211_rx+0x26c/0x940 [mac80211]() [ 14.552522] Rate marked as a VHT rate but data is invalid: MCS: 10, NSS: 2 ... call trace follows ... Signed-off-by: Michal Kazior --- drivers/net/wireless/ath/ath10k/htt_rx.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c index 1b7a04366256..8ba8fa9004cf 100644 --- a/drivers/net/wireless/ath/ath10k/htt_rx.c +++ b/drivers/net/wireless/ath/ath10k/htt_rx.c @@ -643,6 +643,8 @@ struct amsdu_subframe_hdr { __be16 len; } __packed; +#define GROUP_ID_IS_SU_MIMO(x) ((x) == 0 || (x) == 63) + static void ath10k_htt_rx_h_rates(struct ath10k *ar, struct ieee80211_rx_status *status, struct htt_rx_desc *rxd) @@ -650,6 +652,7 @@ static void ath10k_htt_rx_h_rates(struct ath10k *ar, struct ieee80211_supported_band *sband; u8 cck, rate, bw, sgi, mcs, nss; u8 preamble = 0; + u8 group_id; u32 info1, info2, info3; info1 = __le32_to_cpu(rxd->ppdu_start.info1); @@ -692,10 +695,27 @@ static void ath10k_htt_rx_h_rates(struct ath10k *ar, case HTT_RX_VHT_WITH_TXBF: /* VHT-SIG-A1 in info2, VHT-SIG-A2 in info3 TODO check this */ - mcs = (info3 >> 4) & 0x0F; - nss = ((info2 >> 10) & 0x07) + 1; bw = info2 & 3; sgi = info3 & 1; + group_id = (info2 >> 4) & 0x3F; + + if (GROUP_ID_IS_SU_MIMO(group_id)) { + mcs = (info3 >> 4) & 0x0F; + nss = ((info2 >> 10) & 0x07) + 1; + } else { + /* Hardware doesn't decode VHT-SIG-B into Rx descriptor + * so it's impossible to decode MCS. Also since + * firmware consumes Group Id Management frames host + * has no knowledge regarding group/user position + * mapping so it's impossible to pick the correct Nsts + * from VHT-SIG-A1. + * + * Bandwidth and SGI are valid so report the rateinfo + * on best-effort basis. + */ + mcs = 0; + nss = 1; + } status->rate_idx = mcs; status->vht_nss = nss; -- 2.1.4