mac80211: track needed RX chains for channel contexts

On each channel that the device is operating on, it
may need to listen using one or more chains depending
on the SMPS settings of the interfaces using it. The
previous channel context changes completely removed
this ability (before, it was available as the SMPS
mode).

Add per-context tracking of the required static and
dynamic RX chains and notify the driver on changes.
To achieve this, track the chains and SMPS mode used
on each virtual interface and update the channel
context whenever this changes.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 23 insertions, 5 deletions

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 4add50063161..f3f338541b01 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -543,7 +543,7 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
 
         if (!(ifmgd->flags & IEEE80211_STA_DISABLE_11N))
                 ieee80211_add_ht_ie(sdata, skb, assoc_data->ap_ht_param,
-                                    sband, chan, ifmgd->ap_smps);
+                                    sband, chan, sdata->smps_mode);
 
         if (!(ifmgd->flags & IEEE80211_STA_DISABLE_VHT))
                 ieee80211_add_vht_ie(sdata, skb, sband);
@@ -1392,7 +1392,7 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
         ieee80211_recalc_ps(local, -1);
         mutex_unlock(&local->iflist_mtx);
 
-        ieee80211_recalc_smps(local);
+        ieee80211_recalc_smps(sdata);
         ieee80211_recalc_ps_vif(sdata);
 
         netif_tx_start_all_queues(sdata->dev);
@@ -3157,6 +3157,10 @@ static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
         }
 
         if (ht_oper) {
+                const u8 *ht_cap_ie;
+                const struct ieee80211_ht_cap *ht_cap;
+                u8 chains = 1;
+
                 channel_type = NL80211_CHAN_HT20;
 
                 if (sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) {
@@ -3170,8 +3174,22 @@ static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
                                 break;
                         }
                 }
+
+                ht_cap_ie = cfg80211_find_ie(WLAN_EID_HT_CAPABILITY,
+                                             cbss->information_elements,
+                                             cbss->len_information_elements);
+                if (ht_cap_ie && ht_cap_ie[1] >= sizeof(*ht_cap)) {
+                        ht_cap = (void *)(ht_cap_ie + 2);
+                        chains = ieee80211_mcs_to_chains(&ht_cap->mcs);
+                }
+                sdata->needed_rx_chains = min(chains, local->rx_chains);
+        } else {
+                sdata->needed_rx_chains = 1;
         }
 
+        /* will change later if needed */
+        sdata->smps_mode = IEEE80211_SMPS_OFF;
+
         ieee80211_vif_release_channel(sdata);
         return ieee80211_vif_use_channel(sdata, cbss->channel, channel_type,
                                          IEEE80211_CHANCTX_SHARED);
@@ -3485,11 +3503,11 @@ int ieee80211_mgd_assoc(struct ieee80211_sub_if_data *sdata,
 
         if (ifmgd->req_smps == IEEE80211_SMPS_AUTOMATIC) {
                 if (ifmgd->powersave)
-                        ifmgd->ap_smps = IEEE80211_SMPS_DYNAMIC;
+                        sdata->smps_mode = IEEE80211_SMPS_DYNAMIC;
                 else
-                        ifmgd->ap_smps = IEEE80211_SMPS_OFF;
+                        sdata->smps_mode = IEEE80211_SMPS_OFF;
         } else
-                ifmgd->ap_smps = ifmgd->req_smps;
+                sdata->smps_mode = ifmgd->req_smps;
 
         assoc_data->capability = req->bss->capability;
         assoc_data->wmm = bss->wmm_used &&