iwlwifi: enable serialization of synchronous commands

Until now it was only possible to have one synchronous command running at
any time. If a synchronous command is in progress when a second request
arrives then the second command will fail. Create a new mutex specific for
this purpose to only allow one synchronous command at a time, but enable
other commands to wait instead of fail if a synchronous command is in
progress.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 7 insertions, 7 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-hcmd.c b/drivers/net/wireless/iwlwifi/iwl-hcmd.c
index 86783c27d97c..73681c4fefe7 100644
--- a/drivers/net/wireless/iwlwifi/iwl-hcmd.c
+++ b/drivers/net/wireless/iwlwifi/iwl-hcmd.c
@@ -164,15 +164,13 @@ int iwl_send_cmd_sync(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
          /* A synchronous command can not have a callback set. */
         BUG_ON(cmd->callback);
 
-        if (test_and_set_bit(STATUS_HCMD_SYNC_ACTIVE, &priv->status)) {
-                IWL_ERR(priv,
-                        "Error sending %s: Already sending a host command\n",
+        IWL_DEBUG_INFO(priv, "Attempting to send sync command %s\n",
                         get_cmd_string(cmd->id));
-                ret = -EBUSY;
-                goto out;
-        }
+        mutex_lock(&priv->sync_cmd_mutex);
 
         set_bit(STATUS_HCMD_ACTIVE, &priv->status);
+        IWL_DEBUG_INFO(priv, "Setting HCMD_ACTIVE for command %s \n",
+                        get_cmd_string(cmd->id));
 
         cmd_idx = iwl_enqueue_hcmd(priv, cmd);
         if (cmd_idx < 0) {
@@ -193,6 +191,8 @@ int iwl_send_cmd_sync(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
                                 jiffies_to_msecs(HOST_COMPLETE_TIMEOUT));
 
                         clear_bit(STATUS_HCMD_ACTIVE, &priv->status);
+                        IWL_DEBUG_INFO(priv, "Clearing HCMD_ACTIVE for command %s \n",
+                                       get_cmd_string(cmd->id));
                         ret = -ETIMEDOUT;
                         goto cancel;
                 }
@@ -237,7 +237,7 @@ fail:
                 cmd->reply_page = 0;
         }
 out:
-        clear_bit(STATUS_HCMD_SYNC_ACTIVE, &priv->status);
+        mutex_unlock(&priv->sync_cmd_mutex);
         return ret;
 }
 EXPORT_SYMBOL(iwl_send_cmd_sync);