mwifiex: channel switch handling for station

After receiving channel switch announcement from AP, scan and
association on that channel is blocked for DFS_CHAN_MOVE_TIME
(10 seconds). Hence station will be able to connect to the AP,
once it is moved to new channel.

Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Paul Stewart <pstew@chromium.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

6 files changed, 54 insertions, 0 deletions

diff --git a/drivers/net/wireless/mwifiex/fw.h b/drivers/net/wireless/mwifiex/fw.h
index b6fbbf64cf96..1b45aa533300 100644
--- a/drivers/net/wireless/mwifiex/fw.h
+++ b/drivers/net/wireless/mwifiex/fw.h
@@ -245,6 +245,8 @@ enum MWIFIEX_802_11_PRIVACY_FILTER {
 #define HT_BW_20    0
 #define HT_BW_40    1
 
+#define DFS_CHAN_MOVE_TIME      10000
+
 #define HostCmd_CMD_GET_HW_SPEC                       0x0003
 #define HostCmd_CMD_802_11_SCAN                       0x0006
 #define HostCmd_CMD_802_11_GET_LOG                    0x000b
diff --git a/drivers/net/wireless/mwifiex/init.c b/drivers/net/wireless/mwifiex/init.c
index 2fe31dcaa6ef..caaf4bd56b30 100644
--- a/drivers/net/wireless/mwifiex/init.c
+++ b/drivers/net/wireless/mwifiex/init.c
@@ -133,6 +133,9 @@ int mwifiex_init_priv(struct mwifiex_private *priv)
 
         priv->scan_block = false;
 
+        priv->csa_chan = 0;
+        priv->csa_expire_time = 0;
+
         return mwifiex_add_bss_prio_tbl(priv);
 }
 
diff --git a/drivers/net/wireless/mwifiex/main.h b/drivers/net/wireless/mwifiex/main.h
index 95a6f5269c6c..3da73d36acdf 100644
--- a/drivers/net/wireless/mwifiex/main.h
+++ b/drivers/net/wireless/mwifiex/main.h
@@ -513,6 +513,8 @@ struct mwifiex_private {
         u32 mgmt_frame_mask;
         struct mwifiex_roc_cfg roc_cfg;
         bool scan_aborting;
+        u8 csa_chan;
+        unsigned long csa_expire_time;
 };
 
 enum mwifiex_ba_status {
@@ -1021,6 +1023,24 @@ static inline bool mwifiex_is_skb_mgmt_frame(struct sk_buff *skb)
         return (*(u32 *)skb->data == PKT_TYPE_MGMT);
 }
 
+/* This function retrieves channel closed for operation by Channel
+ * Switch Announcement.
+ */
+static inline u8
+mwifiex_11h_get_csa_closed_channel(struct mwifiex_private *priv)
+{
+        if (!priv->csa_chan)
+                return 0;
+
+        /* Clear csa channel, if DFS channel move time has passed */
+        if (jiffies > priv->csa_expire_time) {
+                priv->csa_chan = 0;
+                priv->csa_expire_time = 0;
+        }
+
+        return priv->csa_chan;
+}
+
 int mwifiex_init_shutdown_fw(struct mwifiex_private *priv,
                              u32 func_init_shutdown);
 int mwifiex_add_card(void *, struct semaphore *, struct mwifiex_if_ops *, u8);
diff --git a/drivers/net/wireless/mwifiex/scan.c b/drivers/net/wireless/mwifiex/scan.c
index 284d68bf6acc..c447d9bd1aa9 100644
--- a/drivers/net/wireless/mwifiex/scan.c
+++ b/drivers/net/wireless/mwifiex/scan.c
@@ -575,6 +575,9 @@ mwifiex_scan_channel_list(struct mwifiex_private *priv,
                 return -1;
         }
 
+        /* Check csa channel expiry before preparing scan list */
+        mwifiex_11h_get_csa_closed_channel(priv);
+
         chan_tlv_out->header.type = cpu_to_le16(TLV_TYPE_CHANLIST);
 
         /* Set the temp channel struct pointer to the start of the desired
@@ -604,6 +607,11 @@ mwifiex_scan_channel_list(struct mwifiex_private *priv,
                 while (tlv_idx < max_chan_per_scan &&
                        tmp_chan_list->chan_number && !done_early) {
 
+                        if (tmp_chan_list->chan_number == priv->csa_chan) {
+                                tmp_chan_list++;
+                                continue;
+                        }
+
                         dev_dbg(priv->adapter->dev,
                                 "info: Scan: Chan(%3d), Radio(%d),"
                                 " Mode(%d, %d), Dur(%d)\n",
@@ -1594,6 +1602,9 @@ int mwifiex_ret_802_11_scan(struct mwifiex_private *priv,
                 goto check_next_scan;
         }
 
+        /* Check csa channel expiry before parsing scan response */
+        mwifiex_11h_get_csa_closed_channel(priv);
+
         bytes_left = le16_to_cpu(scan_rsp->bss_descript_size);
         dev_dbg(adapter->dev, "info: SCAN_RESP: bss_descript_size %d\n",
                 bytes_left);
@@ -1746,6 +1757,13 @@ int mwifiex_ret_802_11_scan(struct mwifiex_private *priv,
                         struct ieee80211_channel *chan;
                         u8 band;
 
+                        /* Skip entry if on csa closed channel */
+                        if (channel == priv->csa_chan) {
+                                dev_dbg(adapter->dev,
+                                        "Dropping entry on csa closed channel\n");
+                                continue;
+                        }
+
                         band = BAND_G;
                         if (chan_band_tlv) {
                                 chan_band =
diff --git a/drivers/net/wireless/mwifiex/sta_event.c b/drivers/net/wireless/mwifiex/sta_event.c
index d28c92005cce..ea265ec0e522 100644
--- a/drivers/net/wireless/mwifiex/sta_event.c
+++ b/drivers/net/wireless/mwifiex/sta_event.c
@@ -429,6 +429,9 @@ int mwifiex_process_sta_event(struct mwifiex_private *priv)
 
         case EVENT_CHANNEL_SWITCH_ANN:
                 dev_dbg(adapter->dev, "event: Channel Switch Announcement\n");
+                priv->csa_expire_time =
+                                jiffies + msecs_to_jiffies(DFS_CHAN_MOVE_TIME);
+                priv->csa_chan = priv->curr_bss_params.bss_descriptor.channel;
                 ret = mwifiex_send_cmd_async(priv,
                         HostCmd_CMD_802_11_DEAUTHENTICATE,
                         HostCmd_ACT_GEN_SET, 0,
diff --git a/drivers/net/wireless/mwifiex/sta_ioctl.c b/drivers/net/wireless/mwifiex/sta_ioctl.c
index 498add76a46d..206c3e038072 100644
--- a/drivers/net/wireless/mwifiex/sta_ioctl.c
+++ b/drivers/net/wireless/mwifiex/sta_ioctl.c
@@ -281,6 +281,14 @@ int mwifiex_bss_start(struct mwifiex_private *priv, struct cfg80211_bss *bss,
                 if (ret)
                         goto done;
 
+                if (mwifiex_11h_get_csa_closed_channel(priv) ==
+                                                        (u8)bss_desc->channel) {
+                        dev_err(adapter->dev,
+                                "Attempt to reconnect on csa closed chan(%d)\n",
+                                bss_desc->channel);
+                        goto done;
+                }
+
                 dev_dbg(adapter->dev, "info: SSID found in scan list ... "
                                       "associating...\n");