ath10k: fix mu-mimo rx status reporting

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 <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
This commit is contained in:
Michal Kazior 2015-08-27 14:47:33 +02:00 committed by Kalle Valo
parent ee92a2099f
commit 6986fdd699
1 changed files with 22 additions and 2 deletions
drivers/net/wireless/ath/ath10k

View File

@ -643,6 +643,8 @@ struct amsdu_subframe_hdr {
__be16 len; __be16 len;
} __packed; } __packed;
#define GROUP_ID_IS_SU_MIMO(x) ((x) == 0 || (x) == 63)
static void ath10k_htt_rx_h_rates(struct ath10k *ar, static void ath10k_htt_rx_h_rates(struct ath10k *ar,
struct ieee80211_rx_status *status, struct ieee80211_rx_status *status,
struct htt_rx_desc *rxd) struct htt_rx_desc *rxd)
@ -650,6 +652,7 @@ static void ath10k_htt_rx_h_rates(struct ath10k *ar,
struct ieee80211_supported_band *sband; struct ieee80211_supported_band *sband;
u8 cck, rate, bw, sgi, mcs, nss; u8 cck, rate, bw, sgi, mcs, nss;
u8 preamble = 0; u8 preamble = 0;
u8 group_id;
u32 info1, info2, info3; u32 info1, info2, info3;
info1 = __le32_to_cpu(rxd->ppdu_start.info1); 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: case HTT_RX_VHT_WITH_TXBF:
/* VHT-SIG-A1 in info2, VHT-SIG-A2 in info3 /* VHT-SIG-A1 in info2, VHT-SIG-A2 in info3
TODO check this */ TODO check this */
mcs = (info3 >> 4) & 0x0F;
nss = ((info2 >> 10) & 0x07) + 1;
bw = info2 & 3; bw = info2 & 3;
sgi = info3 & 1; 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->rate_idx = mcs;
status->vht_nss = nss; status->vht_nss = nss;