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alistair23-linux/net/mac80211/vht.c
Johannes Berg 4a817aa78f mac80211: allow VHT with peers not capable of 40MHz 
There are two (related) issues with this.

One case, reported by Michal, is related to hostap: it unsets the
20/40 capability bit for stations that associate when it's in 20
MHz mode.

The other case, reported by Eyal, is that some APs like Netgear
R6300v2 and probably others based on the BCM4360 chipset can be
configured for doing VHT at 20Mhz. In this case the beacon has
a VHT IE but the HT cap indicates transmitter only support 20Mhz.

In both of these cases, we currently avoid VHT and use only HT
this means we can't use the highest rates (MCS8), so fixing this
leads to throughput improvements.

Reported-by: Michal Kazior <michal.kazior@tieto.com>
Reported-by: Eyal Shapira <eyal@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2014-05-09 09:56:53 +02:00

420 lines
12 KiB
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/*
* VHT handling
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/ieee80211.h>
#include <linux/export.h>
#include <net/mac80211.h>
#include "ieee80211_i.h"
#include "rate.h"
static void __check_vhtcap_disable(struct ieee80211_sub_if_data *sdata,
struct ieee80211_sta_vht_cap *vht_cap,
u32 flag)
{
__le32 le_flag = cpu_to_le32(flag);
if (sdata->u.mgd.vht_capa_mask.vht_cap_info & le_flag &&
!(sdata->u.mgd.vht_capa.vht_cap_info & le_flag))
vht_cap->cap &= ~flag;
}
void ieee80211_apply_vhtcap_overrides(struct ieee80211_sub_if_data *sdata,
struct ieee80211_sta_vht_cap *vht_cap)
{
int i;
u16 rxmcs_mask, rxmcs_cap, rxmcs_n, txmcs_mask, txmcs_cap, txmcs_n;
if (!vht_cap->vht_supported)
return;
if (sdata->vif.type != NL80211_IFTYPE_STATION)
return;
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_RXLDPC);
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_SHORT_GI_80);
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_SHORT_GI_160);
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_TXSTBC);
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE);
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE);
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_RX_ANTENNA_PATTERN);
__check_vhtcap_disable(sdata, vht_cap,
IEEE80211_VHT_CAP_TX_ANTENNA_PATTERN);
/* Allow user to decrease AMPDU length exponent */
if (sdata->u.mgd.vht_capa_mask.vht_cap_info &
cpu_to_le32(IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK)) {
u32 cap, n;
n = le32_to_cpu(sdata->u.mgd.vht_capa.vht_cap_info) &
IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK;
n >>= IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_SHIFT;
cap = vht_cap->cap & IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK;
cap >>= IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_SHIFT;
if (n < cap) {
vht_cap->cap &=
~IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK;
vht_cap->cap |=
n << IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_SHIFT;
}
}
/* Allow the user to decrease MCSes */
rxmcs_mask =
le16_to_cpu(sdata->u.mgd.vht_capa_mask.supp_mcs.rx_mcs_map);
rxmcs_n = le16_to_cpu(sdata->u.mgd.vht_capa.supp_mcs.rx_mcs_map);
rxmcs_n &= rxmcs_mask;
rxmcs_cap = le16_to_cpu(vht_cap->vht_mcs.rx_mcs_map);
txmcs_mask =
le16_to_cpu(sdata->u.mgd.vht_capa_mask.supp_mcs.tx_mcs_map);
txmcs_n = le16_to_cpu(sdata->u.mgd.vht_capa.supp_mcs.tx_mcs_map);
txmcs_n &= txmcs_mask;
txmcs_cap = le16_to_cpu(vht_cap->vht_mcs.tx_mcs_map);
for (i = 0; i < 8; i++) {
u8 m, n, c;
m = (rxmcs_mask >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
n = (rxmcs_n >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
c = (rxmcs_cap >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
if (m && ((c != IEEE80211_VHT_MCS_NOT_SUPPORTED && n < c) ||
n == IEEE80211_VHT_MCS_NOT_SUPPORTED)) {
rxmcs_cap &= ~(3 << 2*i);
rxmcs_cap |= (rxmcs_n & (3 << 2*i));
}
m = (txmcs_mask >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
n = (txmcs_n >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
c = (txmcs_cap >> 2*i) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
if (m && ((c != IEEE80211_VHT_MCS_NOT_SUPPORTED && n < c) ||
n == IEEE80211_VHT_MCS_NOT_SUPPORTED)) {
txmcs_cap &= ~(3 << 2*i);
txmcs_cap |= (txmcs_n & (3 << 2*i));
}
}
vht_cap->vht_mcs.rx_mcs_map = cpu_to_le16(rxmcs_cap);
vht_cap->vht_mcs.tx_mcs_map = cpu_to_le16(txmcs_cap);
}
void
ieee80211_vht_cap_ie_to_sta_vht_cap(struct ieee80211_sub_if_data *sdata,
struct ieee80211_supported_band *sband,
const struct ieee80211_vht_cap *vht_cap_ie,
struct sta_info *sta)
{
struct ieee80211_sta_vht_cap *vht_cap = &sta->sta.vht_cap;
struct ieee80211_sta_vht_cap own_cap;
u32 cap_info, i;
memset(vht_cap, 0, sizeof(*vht_cap));
if (!sta->sta.ht_cap.ht_supported)
return;
if (!vht_cap_ie || !sband->vht_cap.vht_supported)
return;
/*
* A VHT STA must support 40 MHz, but if we verify that here
* then we break a few things - some APs (e.g. Netgear R6300v2
* and others based on the BCM4360 chipset) will unset this
* capability bit when operating in 20 MHz.
*/
vht_cap->vht_supported = true;
own_cap = sband->vht_cap;
/*
* If user has specified capability overrides, take care
* of that if the station we're setting up is the AP that
* we advertised a restricted capability set to. Override
* our own capabilities and then use those below.
*/
if (sdata->vif.type == NL80211_IFTYPE_STATION &&
!test_sta_flag(sta, WLAN_STA_TDLS_PEER))
ieee80211_apply_vhtcap_overrides(sdata, &own_cap);
/* take some capabilities as-is */
cap_info = le32_to_cpu(vht_cap_ie->vht_cap_info);
vht_cap->cap = cap_info;
vht_cap->cap &= IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_3895 |
IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_7991 |
IEEE80211_VHT_CAP_MAX_MPDU_LENGTH_11454 |
IEEE80211_VHT_CAP_RXLDPC |
IEEE80211_VHT_CAP_VHT_TXOP_PS |
IEEE80211_VHT_CAP_HTC_VHT |
IEEE80211_VHT_CAP_MAX_A_MPDU_LENGTH_EXPONENT_MASK |
IEEE80211_VHT_CAP_VHT_LINK_ADAPTATION_VHT_UNSOL_MFB |
IEEE80211_VHT_CAP_VHT_LINK_ADAPTATION_VHT_MRQ_MFB |
IEEE80211_VHT_CAP_RX_ANTENNA_PATTERN |
IEEE80211_VHT_CAP_TX_ANTENNA_PATTERN;
/* and some based on our own capabilities */
switch (own_cap.cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK) {
case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ:
vht_cap->cap |= cap_info &
IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ;
break;
case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ:
vht_cap->cap |= cap_info &
IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK;
break;
default:
/* nothing */
break;
}
/* symmetric capabilities */
vht_cap->cap |= cap_info & own_cap.cap &
(IEEE80211_VHT_CAP_SHORT_GI_80 |
IEEE80211_VHT_CAP_SHORT_GI_160);
/* remaining ones */
if (own_cap.cap & IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE)
vht_cap->cap |= cap_info &
(IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE |
IEEE80211_VHT_CAP_SOUNDING_DIMENSIONS_MASK);
if (own_cap.cap & IEEE80211_VHT_CAP_SU_BEAMFORMER_CAPABLE)
vht_cap->cap |= cap_info &
(IEEE80211_VHT_CAP_SU_BEAMFORMEE_CAPABLE |
IEEE80211_VHT_CAP_BEAMFORMEE_STS_MASK);
if (own_cap.cap & IEEE80211_VHT_CAP_MU_BEAMFORMER_CAPABLE)
vht_cap->cap |= cap_info &
IEEE80211_VHT_CAP_MU_BEAMFORMEE_CAPABLE;
if (own_cap.cap & IEEE80211_VHT_CAP_MU_BEAMFORMEE_CAPABLE)
vht_cap->cap |= cap_info &
IEEE80211_VHT_CAP_MU_BEAMFORMER_CAPABLE;
if (own_cap.cap & IEEE80211_VHT_CAP_TXSTBC)
vht_cap->cap |= cap_info & IEEE80211_VHT_CAP_RXSTBC_MASK;
if (own_cap.cap & IEEE80211_VHT_CAP_RXSTBC_MASK)
vht_cap->cap |= cap_info & IEEE80211_VHT_CAP_TXSTBC;
/* Copy peer MCS info, the driver might need them. */
memcpy(&vht_cap->vht_mcs, &vht_cap_ie->supp_mcs,
sizeof(struct ieee80211_vht_mcs_info));
/* but also restrict MCSes */
for (i = 0; i < 8; i++) {
u16 own_rx, own_tx, peer_rx, peer_tx;
own_rx = le16_to_cpu(own_cap.vht_mcs.rx_mcs_map);
own_rx = (own_rx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
own_tx = le16_to_cpu(own_cap.vht_mcs.tx_mcs_map);
own_tx = (own_tx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
peer_rx = le16_to_cpu(vht_cap->vht_mcs.rx_mcs_map);
peer_rx = (peer_rx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
peer_tx = le16_to_cpu(vht_cap->vht_mcs.tx_mcs_map);
peer_tx = (peer_tx >> i * 2) & IEEE80211_VHT_MCS_NOT_SUPPORTED;
if (peer_tx != IEEE80211_VHT_MCS_NOT_SUPPORTED) {
if (own_rx == IEEE80211_VHT_MCS_NOT_SUPPORTED)
peer_tx = IEEE80211_VHT_MCS_NOT_SUPPORTED;
else if (own_rx < peer_tx)
peer_tx = own_rx;
}
if (peer_rx != IEEE80211_VHT_MCS_NOT_SUPPORTED) {
if (own_tx == IEEE80211_VHT_MCS_NOT_SUPPORTED)
peer_rx = IEEE80211_VHT_MCS_NOT_SUPPORTED;
else if (own_tx < peer_rx)
peer_rx = own_tx;
}
vht_cap->vht_mcs.rx_mcs_map &=
~cpu_to_le16(IEEE80211_VHT_MCS_NOT_SUPPORTED << i * 2);
vht_cap->vht_mcs.rx_mcs_map |= cpu_to_le16(peer_rx << i * 2);
vht_cap->vht_mcs.tx_mcs_map &=
~cpu_to_le16(IEEE80211_VHT_MCS_NOT_SUPPORTED << i * 2);
vht_cap->vht_mcs.tx_mcs_map |= cpu_to_le16(peer_tx << i * 2);
}
/* finally set up the bandwidth */
switch (vht_cap->cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK) {
case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ:
case IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ:
sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_160;
break;
default:
sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_80;
}
sta->sta.bandwidth = ieee80211_sta_cur_vht_bw(sta);
}
enum ieee80211_sta_rx_bandwidth ieee80211_sta_cur_vht_bw(struct sta_info *sta)
{
struct ieee80211_sub_if_data *sdata = sta->sdata;
u32 cap = sta->sta.vht_cap.cap;
enum ieee80211_sta_rx_bandwidth bw;
if (!sta->sta.vht_cap.vht_supported) {
bw = sta->sta.ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
goto check_max;
}
switch (sdata->vif.bss_conf.chandef.width) {
default:
WARN_ON_ONCE(1);
/* fall through */
case NL80211_CHAN_WIDTH_20_NOHT:
case NL80211_CHAN_WIDTH_20:
case NL80211_CHAN_WIDTH_40:
bw = sta->sta.ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
break;
case NL80211_CHAN_WIDTH_160:
if ((cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK) ==
IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160MHZ) {
bw = IEEE80211_STA_RX_BW_160;
break;
}
/* fall through */
case NL80211_CHAN_WIDTH_80P80:
if ((cap & IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_MASK) ==
IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ) {
bw = IEEE80211_STA_RX_BW_160;
break;
}
/* fall through */
case NL80211_CHAN_WIDTH_80:
bw = IEEE80211_STA_RX_BW_80;
}
check_max:
if (bw > sta->cur_max_bandwidth)
bw = sta->cur_max_bandwidth;
return bw;
}
void ieee80211_sta_set_rx_nss(struct sta_info *sta)
{
u8 ht_rx_nss = 0, vht_rx_nss = 0;
/* if we received a notification already don't overwrite it */
if (sta->sta.rx_nss)
return;
if (sta->sta.ht_cap.ht_supported) {
if (sta->sta.ht_cap.mcs.rx_mask[0])
ht_rx_nss++;
if (sta->sta.ht_cap.mcs.rx_mask[1])
ht_rx_nss++;
if (sta->sta.ht_cap.mcs.rx_mask[2])
ht_rx_nss++;
if (sta->sta.ht_cap.mcs.rx_mask[3])
ht_rx_nss++;
/* FIXME: consider rx_highest? */
}
if (sta->sta.vht_cap.vht_supported) {
int i;
u16 rx_mcs_map;
rx_mcs_map = le16_to_cpu(sta->sta.vht_cap.vht_mcs.rx_mcs_map);
for (i = 7; i >= 0; i--) {
u8 mcs = (rx_mcs_map >> (2 * i)) & 3;
if (mcs != IEEE80211_VHT_MCS_NOT_SUPPORTED) {
vht_rx_nss = i + 1;
break;
}
}
/* FIXME: consider rx_highest? */
}
ht_rx_nss = max(ht_rx_nss, vht_rx_nss);
sta->sta.rx_nss = max_t(u8, 1, ht_rx_nss);
}
u32 __ieee80211_vht_handle_opmode(struct ieee80211_sub_if_data *sdata,
struct sta_info *sta, u8 opmode,
enum ieee80211_band band, bool nss_only)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_supported_band *sband;
enum ieee80211_sta_rx_bandwidth new_bw;
u32 changed = 0;
u8 nss;
sband = local->hw.wiphy->bands[band];
/* ignore - no support for BF yet */
if (opmode & IEEE80211_OPMODE_NOTIF_RX_NSS_TYPE_BF)
return 0;
nss = opmode & IEEE80211_OPMODE_NOTIF_RX_NSS_MASK;
nss >>= IEEE80211_OPMODE_NOTIF_RX_NSS_SHIFT;
nss += 1;
if (sta->sta.rx_nss != nss) {
sta->sta.rx_nss = nss;
changed |= IEEE80211_RC_NSS_CHANGED;
}
if (nss_only)
return changed;
switch (opmode & IEEE80211_OPMODE_NOTIF_CHANWIDTH_MASK) {
case IEEE80211_OPMODE_NOTIF_CHANWIDTH_20MHZ:
sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_20;
break;
case IEEE80211_OPMODE_NOTIF_CHANWIDTH_40MHZ:
sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_40;
break;
case IEEE80211_OPMODE_NOTIF_CHANWIDTH_80MHZ:
sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_80;
break;
case IEEE80211_OPMODE_NOTIF_CHANWIDTH_160MHZ:
sta->cur_max_bandwidth = IEEE80211_STA_RX_BW_160;
break;
}
new_bw = ieee80211_sta_cur_vht_bw(sta);
if (new_bw != sta->sta.bandwidth) {
sta->sta.bandwidth = new_bw;
changed |= IEEE80211_RC_BW_CHANGED;
}
return changed;
}
void ieee80211_vht_handle_opmode(struct ieee80211_sub_if_data *sdata,
struct sta_info *sta, u8 opmode,
enum ieee80211_band band, bool nss_only)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_supported_band *sband = local->hw.wiphy->bands[band];
u32 changed = __ieee80211_vht_handle_opmode(sdata, sta, opmode,
band, nss_only);
if (changed > 0)
rate_control_rate_update(local, sband, sta, changed);
}
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