iwlwifi: mvm: allow to force the Rx chains from debugfs

This is useful to debug weird antenna problems.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

3 files changed, 57 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/mvm/debugfs-vif.c b/drivers/net/wireless/iwlwifi/mvm/debugfs-vif.c
index 5fe14591e1c4..7faad90386b8 100644
--- a/drivers/net/wireless/iwlwifi/mvm/debugfs-vif.c
+++ b/drivers/net/wireless/iwlwifi/mvm/debugfs-vif.c
@@ -545,6 +545,57 @@ static ssize_t iwl_dbgfs_uapsd_misbehaving_write(struct ieee80211_vif *vif,
         return ret ? count : -EINVAL;
 }
 
+static ssize_t iwl_dbgfs_rx_phyinfo_write(struct ieee80211_vif *vif, char *buf,
+                                          size_t count, loff_t *ppos)
+{
+        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+        struct iwl_mvm *mvm = mvmvif->mvm;
+        struct ieee80211_chanctx_conf *chanctx_conf;
+        struct iwl_mvm_phy_ctxt *phy_ctxt;
+        u16 value;
+        int ret;
+
+        ret = kstrtou16(buf, 0, &value);
+        if (ret)
+                return ret;
+
+        mutex_lock(&mvm->mutex);
+        rcu_read_lock();
+
+        chanctx_conf = rcu_dereference(vif->chanctx_conf);
+        /* make sure the channel context is assigned */
+        if (!chanctx_conf) {
+                rcu_read_unlock();
+                mutex_unlock(&mvm->mutex);
+                return -EINVAL;
+        }
+
+        phy_ctxt = &mvm->phy_ctxts[*(u16 *)chanctx_conf->drv_priv];
+        rcu_read_unlock();
+
+        mvm->dbgfs_rx_phyinfo = value;
+
+        ret = iwl_mvm_phy_ctxt_changed(mvm, phy_ctxt, &chanctx_conf->min_def,
+                                       chanctx_conf->rx_chains_static,
+                                       chanctx_conf->rx_chains_dynamic);
+        mutex_unlock(&mvm->mutex);
+
+        return ret ?: count;
+}
+
+static ssize_t iwl_dbgfs_rx_phyinfo_read(struct file *file,
+                                         char __user *user_buf,
+                                         size_t count, loff_t *ppos)
+{
+        struct ieee80211_vif *vif = file->private_data;
+        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+        char buf[8];
+
+        snprintf(buf, sizeof(buf), "0x%04x\n", mvmvif->mvm->dbgfs_rx_phyinfo);
+
+        return simple_read_from_buffer(user_buf, count, ppos, buf, sizeof(buf));
+}
+
 #define MVM_DEBUGFS_WRITE_FILE_OPS(name, bufsz) \
         _MVM_DEBUGFS_WRITE_FILE_OPS(name, bufsz, struct ieee80211_vif)
 #define MVM_DEBUGFS_READ_WRITE_FILE_OPS(name, bufsz) \
@@ -560,6 +611,7 @@ MVM_DEBUGFS_READ_WRITE_FILE_OPS(pm_params, 32);
 MVM_DEBUGFS_READ_WRITE_FILE_OPS(bf_params, 256);
 MVM_DEBUGFS_READ_WRITE_FILE_OPS(low_latency, 10);
 MVM_DEBUGFS_READ_WRITE_FILE_OPS(uapsd_misbehaving, 20);
+MVM_DEBUGFS_READ_WRITE_FILE_OPS(rx_phyinfo, 10);
 
 void iwl_mvm_vif_dbgfs_register(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
 {
@@ -595,6 +647,8 @@ void iwl_mvm_vif_dbgfs_register(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
                                  S_IRUSR | S_IWUSR);
         MVM_DEBUGFS_ADD_FILE_VIF(uapsd_misbehaving, mvmvif->dbgfs_dir,
                                  S_IRUSR | S_IWUSR);
+        MVM_DEBUGFS_ADD_FILE_VIF(rx_phyinfo, mvmvif->dbgfs_dir,
+                                 S_IRUSR | S_IWUSR);
 
         if (vif->type == NL80211_IFTYPE_STATION && !vif->p2p &&
             mvmvif == mvm->bf_allowed_vif)
diff --git a/drivers/net/wireless/iwlwifi/mvm/mvm.h b/drivers/net/wireless/iwlwifi/mvm/mvm.h
index f78a006df0e9..885d09692fb6 100644
--- a/drivers/net/wireless/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/iwlwifi/mvm/mvm.h
@@ -681,6 +681,7 @@ struct iwl_mvm {
 
         struct iwl_mvm_frame_stats drv_rx_stats;
         spinlock_t drv_stats_lock;
+        u16 dbgfs_rx_phyinfo;
 #endif
 
         struct iwl_mvm_phy_ctxt phy_ctxts[NUM_PHY_CTX];
diff --git a/drivers/net/wireless/iwlwifi/mvm/phy-ctxt.c b/drivers/net/wireless/iwlwifi/mvm/phy-ctxt.c
index 5b43616eeb06..1bd10eda01f9 100644
--- a/drivers/net/wireless/iwlwifi/mvm/phy-ctxt.c
+++ b/drivers/net/wireless/iwlwifi/mvm/phy-ctxt.c
@@ -175,6 +175,8 @@ static void iwl_mvm_phy_ctxt_cmd_data(struct iwl_mvm *mvm,
         cmd->rxchain_info |= cpu_to_le32(idle_cnt << PHY_RX_CHAIN_CNT_POS);
         cmd->rxchain_info |= cpu_to_le32(active_cnt <<
                                          PHY_RX_CHAIN_MIMO_CNT_POS);
+        if (unlikely(mvm->dbgfs_rx_phyinfo))
+                cmd->rxchain_info = cpu_to_le32(mvm->dbgfs_rx_phyinfo);
 
         cmd->txchain_info = cpu_to_le32(iwl_mvm_get_valid_tx_ant(mvm));
 }